Watermelon variety nun 31813 wmw

ABSTRACT

A new and distinct variety of watermelon variety NUN 31813 WMW is disclosed as well as seeds and plants and fruits thereof. NUN 31813 is a triploid, round small, crimson sweet type watermelon variety, comprising intermediate resistance to  Fusarium oxysporum  f. s.p  niveum  Race 0,  Fusarium oxysporum  f. s.p  niveum  Race 1, and  Colletotrichum lagenarium  Race 1.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/961,995, filed on Jan. 16, 2020, which is hereby incorporated inreference to its entirety.

FIELD OF THE DISCLOSURE

The disclosure relates to the field of plant breeding and, morespecifically, to watermelon variety NUN 31813 WMW. The disclosurefurther relates to vegetative reproductions of watermelon variety NUN31813 WMW, methods for tissue culture of watermelon variety NUN 31813WMW and regenerating a plant from such a tissue culture and tophenotypic variants of watermelon variety NUN 31813 WMW. The disclosurealso relates to progeny of watermelon variety NUN 31813 WMW and thehybrid varieties obtained by crossing watermelon variety NUN 31813 WMWas a parent line with plants of other varieties or parent lines.

BACKGROUND OF THE DISCLOSURE

The goal of plant breeding is to combine various desirable traits in asingle variety. Such desirable traits may include greater yield,resistance to diseases, insects or other pests, tolerance to heat anddrought, better agronomic quality, higher nutritional value, enhancedgrowth rate, and improved fruit properties.

Breeding techniques take advantage of a plant's method of pollination.There are two general methods of pollination: a plant self-pollinates ifpollen from one flower is transferred to the same or another flower ofthe same genotype. A plant cross-pollinates if pollen comes to it from aflower of a different genotype. Plants that have been self-pollinatedand selected for (uniform) type over many generations become homozygousat almost all gene loci and produce a uniform population of truebreeding progeny of homozygous plants. A cross between two suchhomozygous plants of different lines produces a uniform population ofhybrid plants that are heterozygous for many gene loci. The extent ofheterozygosity in the hybrid is a function of the genetic distancebetween the parents. Conversely, a cross of two plants each heterozygousat a number of loci produces a segregating population of hybrid plantsthat differ genetically and are not uniform. The resultingnon-uniformity makes performance unpredictable.

The development of uniform varieties requires the development ofhomozygous inbred plants, the crossing of these inbred plants to makehybrids, and the evaluation of the hybrids resulting from the crosses.Pedigree breeding and recurrent selection are examples of breedingmethods that have been used to develop inbred plants from breedingpopulations. Those breeding methods combine the genetic backgrounds fromtwo or more plants or various other broad-based sources into breedingpools from which new lines are developed by selfing and selection ofdesired phenotypes. The new plants are evaluated to determine which havecommercial potential.

One valuable crop that has been subject to breeding programs iswatermelon, a member of the Cucurbitacea family. The genus Citrullusoriginated in Africa. The plant is a large and sprawling annual, grownfor its fruit. The fruit of watermelon is often colored attractively,commonly red. Watermelon can contain black seeds, which are consideredundesirable for certain uses. Watermelon is primarily consumed fresh.The fruit can be eaten fresh as dessert, snack, salad, or juice.Watermelon is also processed to produce roasted seeds, pickled rind,pickled fruit, or powdered juice.

Watermelon (Citrullus lanatus) can occur as a diploid, triploid, ortetraploid. Seedless watermelon fruits are produced by using pollen fromdiploid male parent plants to fertilize flowers of tetraploid maternalparent plants. Pollination of the tetraploid flowers with diploid pollenleads to hybrid F1 seeds which are triploid (see, e.g., Kihara, 1951,Proceedings of American Society for Horticultural Science 58: 217-230;Eigsti 1971, Hort Science 6: 1-2). The triploid hybrid plants grown fromthese F1 seeds are self-infertile as they produce sterile pollen due tochromosome imbalance and need to be pollinated by a diploid pollenizerto produce watermelon fruit. Triploid plants are, therefore,interplanted with pollenizer plants for fruit production. The “seedless”fruit produced after pollination on the triploid hybrid plant are nottruly seedless, but often contain some undeveloped, small, pale seeds,which are edible. Plants are generally planted at a ratio of 1pollenizer per every 2-4 triploid plants. Triploid plants andpollenizers are either planted in separate rows (e.g., 1 row ofpollenizer and 2-4 rows of triploids), or interplanted within rows(e.g., planting 1 pollenizer plant in between 2 to 3 triploid plants inthe same row), or interplanted in narrow rows between rows of triploids(see, e.g., Table 2 of US2006/0168701 and U.S. Pat. No. 8,418,637, whichis herein incorporated by reference in their entireties). The fruitproduced on the pollenizer plants preferably has a different rindpattern from the fruit on the triploid hybrids, so that these can beeasily distinguished.

Grading of fruits is usually done by fruit weight, to distinguish “mini”watermelons, with weights of less than 6 pounds (2.72 kg), “icebox”watermelons with weights of 8-12 pounds (3.62 kg-5.44 kg) or, accordingto others, of 6 to 15 pounds (2.72 kg to 6.8 kg) and “picnic”watermelons of above the icebox size, so either above 12 pounds (above5.44 kg) or above 15 pounds (above 6.8 kg). Furthermore, watermelonfruit flesh can have various colors, including various tints of red,pink, orange, and yellow.

Watermelons are produced across the United States with the most volumeof production coming from Texas, Florida, Georgia, and California. Theconsumer demand for watermelon, in particular for seedless (triploid)varieties is continuously growing due to its health benefits. Thistranslates to an increased demand for improved watermelon varieties ofdifferent sizes, shapes, and fruit quality. Other objectives includevarying the color, texture, and flavor of the fruit, absence of seeds,disease or pest resistance, optimizing flesh thickness, yield,suitability to various climatic circumstances, solid content (% drymatter), and sugar content.

SUMMARY OF VARIOUS EMBODIMENTS OF THE DISCLOSURE

The disclosure provides for watermelon variety NUN 31813 WMW, productsthereof, and methods of using the same. NUN 31813 is a triploid, roundsmall, crimson sweet type watermelon variety and is suitable for growingin the open field. Watermelon variety NUN 31813 WMW has small pips, firmflesh and has low percentage of hollow heart.

In another aspect, the disclosure provides a seed of watermelon varietyNUN 31813 WMW, wherein a representative sample of said seed has beendeposited under Accession Number NCIMB ______. The disclosure alsoprovides for a plurality of seeds of watermelon variety NUN 31813 WMW.The watermelon seed of variety NUN 31813 WMW may be provided as anessentially homogeneous population of watermelon seed. The population ofseed of variety NUN 31813 WMW may be particularly defined as essentiallyfree from other seed. The seed population may be grown into plants toprovide an essentially homogeneous population of watermelon plants asdescribed herein.

The disclosure also provides a plant grown from a seed of watermelonvariety NUN 31813 WMW and plant part thereof.

The disclosure further provides a watermelon fruit produced on a plantgrown from a seed of watermelon variety NUN 31813 WMW.

In another aspect, the disclosure provides a seed growing or grown on aplant of variety NUN 31813 WMW (i.e., produced after pollination of theflower of watermelon variety NUN 31813 WMW).

In another aspect, the disclosure provides for a plant part obtainedfrom watermelon variety NUN 31813 WMW, wherein said plant part is: afruit, a harvested fruit, a part of a fruit, a leaf, a part of a leaf,pollen, an ovule, a cell, a petiole, a shoot or a part thereof, a stemor a part thereof, a root or a part thereof, a root tip, a cutting, aseed, a part of a seed, seed coat or another maternal tissue which ispart of a seed grown on said variety, a hypocotyl, a cotyledon, a scion,a stock, a rootstock, a pistil, an anther, or a flower or a partthereof. Fruits are particularly important plant parts. Such plant partsmay be suitable for sexual reproduction, vegetative reproduction, or atissue culture. In another aspect, the plant part obtained from varietyNUN 31813 WMW is a cell, optionally a cell in a cell or tissue culture.That cell may be grown into a plant of variety NUN 31813 WMW.

In another aspect, the disclosure provides for a hybrid watermelonvariety NUN 31813 WMW. The disclosure also provides for a progeny ofwatermelon variety NUN 31813 WMW. In another aspect, the disclosureprovides a plant or a progeny retaining all or all but one, two or threeof the “distinguishing characteristics” or all or all but one, two orthree of the “morphological and physiological characteristics” ofwatermelon variety NUN 31813 WMW and methods for producing that plant orprogeny.

In another aspect, the disclosure provides a plant or a progeny havingall the physiological and morphological characteristics of watermelonvariety NUN 31813 WMW when grown under the same environmentalconditions. In another aspect, the plant or progeny has all or all butone, two, or three of the physiological and morphologicalcharacteristics of watermelon variety NUN 31813 WMW when measured underthe same environmental conditions and e.g., evaluated at significancelevels of 1%, 5%, or 10% significance (which can also be expressed as ap-value) for quantitative characteristics and determined by type ordegree for non-quantitative characteristics, wherein a representativesample of seed of watermelon variety NUN 31813 WMW has been depositedunder Accession Number NCIMB ______. In another aspect, the plant orprogeny has all or all but one, two, or three of the physiological andmorphological characteristics as listed in Tables 1-2 for watermelonvariety NUN 31813 WMW when measured under the same environmentalconditions and e.g., evaluated at significance levels of 1%, 5%, or 10%significance (which can also be expressed as a p-value) for quantitativecharacteristics and determined by type or degree for non-quantitativecharacteristics.

In another aspect, the plant of variety NUN 31813 WMW or progeny thereofhas 18, 19, or more or all of the following distinguishingcharacteristics as shown in Table 3 when compared to the ReferenceVariety: 1) round small fruit type; 2) thinner stem at second node; 3)shorter mature leaf; 4) stronger blade lobing; 5) weaker bladeblistering; 6) round mature fruit shape; 7) shorter mature fruit; 8)smaller fruit; 9) lighter mature fruit; 10) darker yellow green maturefruit primary color; 11) darker green mature fruit secondary color; 12)broad elliptic mature fruit shape in longitudinal section; 13) only onecolored pattern of stripes; 14) broad to very broad stripes; 15) shorterpeduncle; 16) thinner peduncle; 17) thinner rind at side; 18) thinnerrind at stem end, and 19) Fusarium oxysporum f. sp. niveum Race 0, whendetermined at 5% significance level for numerical characteristics anddetermined by type or degree for non-numerical characteristics forplants grown under the same environmental conditions.

In another aspect, the plant of watermelon variety NUN 31813 WMW or partthereof or progeny thereof comprises intermediate resistance to Fusariumoxysporum f. sp. niveum Race 0, Fusarium oxysporum f. s.p niveum Race 1,and Colletotrichum lagenarium Race 1, measured according to UPOVstandards described in TG/142/5.

The disclosure also provides a cell culture of watermelon variety NUN31813 WMW and a plant regenerated from watermelon variety NUN 31813 WMW,which plant has all the characteristics of watermelon variety NUN 31813WMW when grown under the same environmental conditions, as well asmethods for culturing and regenerating watermelon variety NUN 31813 WMW.Alternatively, a regenerated plant may have one characteristic that isdifferent from watermelon variety NUN 31813 WMW.

The disclosure further provides a vegetatively propagated plant ofvariety NUN 31813 WMW having all or all but one, two or three of themorphological and physiological characteristics of watermelon varietyNUN 31813 WMW when grown under the same environmental conditions as wellas methods for vegetatively propagating watermelon variety NUN 31813WMW.

In another aspect, the disclosure provides a method of producing awatermelon plant comprising crossing watermelon variety NUN 31813 WMWwith itself or with another watermelon variety and selecting a progenywatermelon plant from said crossing.

The disclosure also provides a method of producing a melon plant derivedfrom watermelon variety NUN 31813 WMW.

In further aspect, the disclosure provides a method of producing ahybrid watermelon seed comprising crossing a first parent watermelonplant with a second parent watermelon plant and harvesting the resultanthybrid watermelon seed, wherein said first parent plant or second parentwatermelon plant is watermelon variety NUN 31813 WMW. Also provided is ahybrid watermelon seed produced from crossing a first parent watermelonplant and second parent watermelon plant and harvesting the resultanthybrid watermelon seed, wherein said first parent plant or second parentwatermelon plant is watermelon variety NUN 31813 WMW. Moreover, thehybrid watermelon plant grown from the hybrid watermelon seed isprovided.

In another aspect, the disclosure provides a method of introducing asingle locus conversion into the plant of variety NUN 31813 WMW, whereina representative sample of seed of said watermelon variety has beendeposited under Accession Number NCIMB ______, wherein the single locusconverted plant otherwise retains all of the physiological andmorphological characteristics of watermelon variety NUN 31813 WMW andfurther comprises the single locus conversion.

In yet another aspect, the disclosure provides a method for introducinga desired trait into watermelon variety NUN 31813 WMW, said methodcomprises transforming the plant of variety NUN 31813 WMW with atransgene that confers the desired trait, wherein the transformed plantotherwise has all of the physiological and morphological characteristicsof watermelon variety NUN 31813 WMW and contains the desired trait.

The disclosure also provides a method of producing a modified watermelonplant with a desired trait, wherein the method comprises mutating awatermelon plant or plant part of watermelon variety NUN 31813 WMW,wherein a representative sample of seed of said watermelon variety hasbeen deposited under Accession Number NCIMB ______, and wherein themutated plant otherwise retains all of the physiological andmorphological characteristics of watermelon variety NUN 31813 WMW andcontains the desired trait.

In one aspect, the single locus conversion or desired trait is yield,storage properties, color, flavor, size, firmness, enhanced nutritionalquality, post-harvest quality, male sterility, herbicide tolerance,insect resistance, pest resistance, disease resistance, environmentalstress tolerance, modified carbohydrate metabolism, modified proteinmetabolism, or ripening.

In another aspect, the disclosure provides a container comprising theplant, plant part, or seed of watermelon variety NUN 31813 WMW.

Also provided is a food, a feed, or a processed product comprising aplant part of watermelon variety NUN 31813 WMW, wherein the plant partis a fruit or part thereof.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows the mature leaf comparison of watermelon variety NUN 31813WMW and the Reference Variety.

FIG. 2 shows the mature fruit of watermelon variety NUN 31813 WMW.

FIG. 3 shows the mature fruit of the Reference Variety.

FIG. 4 shows the mature fruit comparison of watermelon variety NUN 31813WMW and the Reference Variety.

FIG. 5 shows the cross-section of the mature fruits of watermelonvariety NUN 31813 WMW.

FIG. 6 shows the cross-section of the mature fruit of the ReferenceVariety.

FIG. 7 shows the cross-section comparison of the mature fruit ofwatermelon variety NUN 31813 WMW and the Reference Variety.

DEFINITIONS

“Watermelon” refers herein to plants of the species Citrullus lanatus.The most commonly eaten part of a watermelon is the fruit. The fruitcomprises a stem and peduncle or pedicel, receptacle, ectocarp, rind,fruit flesh, exocarp, mesocarp, external phloem, internal phloem, xylem,vascular bundle, carpel, placenta and optionally seed. The stem andpeduncle or pedicel, receptacle, ectocarp, rind, fruit flesh, exocarp,mesocarp, external phloem, internal phloem, xylem, vascular bundle,carpel, placenta and seedcoat of the seed are maternal tissues, andgenetically identical to the plant on which they grow.

“Cultivated watermelon” refers to plants of Citrullus lanatus (e.g.,varieties, breeding lines or cultivars of the species C. lanatus),cultivated by humans and having good agronomic characteristics.

The terms “watermelon plant designated NUN 31813 WMW,” “NUN 31813 WMW,”“NUN 31813,” “NUN 31813 F1,” “31813 WMW” or “watermelon 31813” are usedinterchangeably herein and refer to a watermelon plant of variety NUN31813 WMW, representative seed of which has been deposited underAccession Number NCIMB ______.

“Plant” includes the whole plant or any part or derivatives thereof,preferably having the same genetic makeup as the plant from which it isobtained.

“Plant part” includes any part of a plant, such as a plant organ (e.g.,harvested or non-harvested fruits), a plant cell, a plant protoplast, aplant cell tissue culture or a tissue culture from which a whole plantcan be regenerated, a plant cell that is intact in a plant, a clone, amicropropagation, plant callus, a plant cell clump, a plant transplant,a vegetative propagation, a seedling, a fruit, a harvested fruit, a partof a fruit, a leaf, a part of a leaf, pollen, an ovule, an embryo, apetiole, a shoot or a part thereof, a stem or a part thereof, a root ora part thereof, a root tip, a cutting, a seed, a part of a seed, ahypocotyl, a cotyledon, a scion, a graft, a stock, a rootstock, apistil, an anther, or a flower or part thereof. Seed can be mature orimmature. Pollen or ovules may be viable or non-viable. Also, anydevelopmental stage is included, such as seedlings, cuttings prior orafter rooting, mature plants or leaves. Alternatively, a plant part mayalso include a plant seed which comprises maternal tissues of watermelonvariety NUN 31813 WMW and an embryo having one or two sets ofchromosomes derived from the parent plant, e.g., from watermelon varietyNUN 31813 WMW. Such an embryo comprises two sets of chromosomes derivedfrom watermelon variety NUN 31813 WMW, if it is produced fromself-pollination of watermelon variety NUN 31813 WMW, while an embryoderived from cross-fertilization of watermelon variety NUN 31813 WMWwill comprise only one set of chromosomes from said variety.

A “seed of NUN 31813 WMW” refers to a watermelon seed which can be growninto a plant of variety NUN 31813 WMW, wherein a representative sampleof viable seed of variety NUN 31813 WMW has been deposited underAccession Number NCIMB ______. A seed can be in any stage of maturity,for example, a mature, viable seed, or an immature, non-viable seed. Aseed comprises an embryo and maternal tissues.

An “embryo of NUN 31813 WMW” refers to an “F1 hybrid embryo” as presentin a seed of watermelon variety NUN 31813 WMW, a representative sampleof said seed of said watermelon variety has been deposited underAccession Number NCIMB ______.

A “seed grown on NUN 31813 WMW” refers to a seed grown on a mature plantof variety NUN 31813 WMW or inside a fruit of watermelon variety NUN31813 WMW. The “seed grown on NUN 31813 WMW” contains tissues and DNA ofthe maternal parent, watermelon variety NUN 31813 WMW.

A “fruit of NUN 31813 WMW” refers to a fruit containing maternal tissuesof watermelon variety NUN 31813 WMW as deposited under Accession NumberNCIMB ______. In one option, the fruit contains seed grown on watermelonvariety NUN 31813 WMW. In another option, the fruit does not containseed, i.e., the fruit is parthenocarpic. The skilled person is familiarwith methods for inducing parthenocarpy. Those methods comprisechemically or genetically inducing parthenocarpy, or by use ofirradiated pollen (see, e.g., Moussa and Salem, 2010). Compoundssuitable for chemically inducing parthenocarpy include auxins,gibberellins and cytokinins (see, e.g., Hayata et al., 1995). A fruitcan be in any stage of maturity, for example, a mature fruit in thestage comprising viable seed, or an immature fruit comprising non-viableseed.

An “essentially homogeneous population of watermelon seed” is apopulation of seeds where at least 97%, 98%, 99% or more of the totalpopulation of seed are seed of watermelon variety NUN 31813 WMW.

An “essentially homogeneous population of watermelon plants” is apopulation of plants where at least 97%, 98%, 99% or more of the totalpopulation of plants are plants of variety NUN 31813 WMW.

The phrase “essentially free from other seed” refers to a population ofseed where less than 3%, 2%, 1% or less of the total population of seedis seed that is not a watermelon seed or, in another aspect, less than3%, 2%, 1% or less of the total population of seed is seed that is notseed of watermelon variety NUN 31813 WMW.

“Flavor” refers to the sensory impression of a food or other substance,especially a watermelon fruit or fruit part (fruit flesh) and isdetermined mainly by the chemical senses of taste and smell. Flavor isinfluenced by texture properties and by volatile and/or non-volatilechemical components (organic acids, lipids, carbohydrates, salts etc.).

“Aroma” refers to smell (or odor) characteristics of watermelon fruitsor fruit parts (fruit flesh).

“Harvest maturity” is referred to as the stage at which a watermelonfruit is ripe or ready for harvest or the optimal time to harvest thefruit for the market, for processing or for consumption. In one aspect,harvest maturity is the stage which allows proper completion of thenormal ripening.

“Harvested plant material” refers herein to plant parts (e.g., fruitsdetached from the whole plant), which have been collected for furtherstorage and/or further use.

“Yield” means the total weight of all watermelon fruits harvested perhectare of a particular line or variety. It is understood that “yield”expressed as weight of all watermelon fruits harvested per hectare canbe obtained by multiplying the number of plants per hectare times the“yield per plant.”

“Marketable yield” means the total weight of all marketable watermelonfruits, especially fruit which is not cracked, damaged or diseased,harvested per hectare of a particular line or variety. A “marketablefruit” is a fruit that has commercial value.

“Hollow heart” is a disorder that varies among varieties. Hollow heartis marked by cracks in the heart of the watermelon fruit owing toaccelerated growth in response to ideal growth conditions facilitated byample water and arm temperatures.

“USDA descriptors” are the plant variety descriptors for Watermelon inthe “Objective Description of Variety—Watermelon (Citrullus lanatus),”as published by the US Department of Agriculture, Agricultural MarketingService, Plant Variety Protection Office, Beltsville, Md. 20705 andwhich can be downloaded from the world-wide web atams.usda.gov/sites/under services/plant-variety-protection/pvpo-c-formsunder watermelon. “Non-USDA descriptors” are other descriptors suitablefor describing watermelon.

“UPOV descriptors” are the plant variety descriptors described forwatermelon in the “Guidelines for the Conduct of Tests for Distinctness,Uniformity and Stability, TG/142/5 (Geneva, 2013 and last revised 2019),as published by UPOV (International Union for the Protection of NewVarieties and Plants), and which can be downloaded from the world-wideweb at upov.int/edocs/tgdocs/en/tg142.pdf and is herein incorporated byreference in its entirety. Likewise, “UPOV methods” to determine thespecific parameters for the characterization of melon are described atupov.int.

“Calibration Manual: DUS Test for Watermelon (Citrillus lanatus)” refersto the calibration book for watermelon which provides guidance fordescribing a watermelon variety, as published by Naktuinbow (August2017). The calibration manual was established by Naktuinbow incollaboration with the National Agriculture and Food ResearchOrganization (NARO)/NCSS (Japan) and based on UPOV TG/142/5.

“RHS” or “RHS color chart” refers to the color chart of the RoyalHorticultural Society (UK), which publishes a botanical color chartquantitatively identifying colors by a defined numbering system. Thechart may be purchased from Royal Horticulture Society Enterprise Ltd.RHS Garden; Wisley, Woking; Surrey GU236QB, UK, e.g., the RHS colorchart 2007.

“Reference Variety for NUN 31813 WMW” refers herein to watermelonvariety NUN 31208 WMW, a variety from Nunhems B. V., with the commercialname Embasy, which has been planted in a trial together with watermelonvariety NUN 31813 WMW. The characteristics of watermelon variety NUN31813 WMW were compared to the characteristics of the Reference Varietyas shown in Tables 1 and 2. The distinguishing characteristics betweenwatermelon variety NUN 31813 WMW and the Reference Variety are shown inTable 3.

A plant having “all the physiological and morphological characteristics”of a referred-to-plant means a plant showing the physiological andmorphological characteristics of the referred-to-plant when grown underthe same environmental conditions, preferably in the same experiment;the referred-to-plant can be a plant from which it was derived, e.g.,the progenitor plant, the parent, the recurrent parent, the plant usedfor tissue- or cell culture, etc. A physiological or morphologicalcharacteristic can be a numerical characteristic or a non-numericalcharacteristic. In one aspect, a plant has “all but one, two or three ofthe physiological and morphological characteristics” of areferred-to-plant, or “all the physiological and morphologicalcharacteristics” of Tables 1-2 or “all or all but one, two or three ofthe physiological and morphological characteristics” of Tables 1-2.

The physiological and/or morphological characteristics mentioned aboveare commonly evaluated at significance levels of 1%, 5% or 10% if theyare numerical (quantitative), or for having an identical degree (ortype) if not numerical (not quantitative), if measured under the sameenvironmental conditions. For example, a progeny plant or a Single LocusConverted plant or a mutated plant of variety NUN 31813 WMW may have oneor more (or all) of the essential physiological and/or morphologicalcharacteristics of said variety listed in Tables 1-2, as determined atthe 5% significance level (i.e., p<0.05), when grown under the sameenvironmental conditions.

“Distinguishing characteristics” or “distinguishing morphological and/orphysiological characteristics” refers herein to the characteristicswhich distinguish the new variety from other watermelon varieties, suchas the Reference Variety (e.g., are different), when grown under thesame environmental conditions. The distinguishing characteristicsbetween watermelon variety NUN 31813 WMW and Reference Variety aredescribed herein and also can be seen in Table 3. When comparingwatermelon variety NUN 31813 WMW to other varieties, the distinguishingcharacteristics may be different. In one aspect, the distinguishingcharacteristics may include one, two, three or more (or all) of thecharacteristics listed in Tables 1-2. All numerical distinguishingcharacteristics are statistically significantly different at p<0.05between NUN 31813 WMW and the other variety, (e.g. the ReferenceVariety).

Watermelon variety NUN 31813 WMW has the following distinguishingcharacteristics when compared to the Reference Variety as shown in Table3: 1) round small fruit type; 2) thinner stem at second node; 3) shortermature leaf; 4) stronger blade lobing; 5) weaker blade blistering; 6)round mature fruit shape; 7) shorter mature fruit; 8) smaller fruit; 9)lighter mature fruit; 10) darker yellow green mature fruit primarycolor; 11) darker green mature fruit secondary color; 12) broad ellipticmature fruit shape in longitudinal section; 13) only one colored patternof stripes; 14) broad to very broad stripes; 15) shorter peduncle; 16)thinner peduncle; 17) thinner rind at side; 18) thinner rind at stemend; and 19) Fusarium oxysporum f. sp. niveum Race 0, when determined at5% significance level for numerical characteristics and determined bytype or degree for non-numerical characteristics for plants grown underthe same environmental conditions

Thus, a watermelon plant “comprising the distinguishing characteristicsof variety NUN 31813 WMW” (such as a progeny plant) refers herein to aplant which does not differ significantly from said variety in thedistinguishing characteristics above. Therefore, in one aspect a plantis provided which does not differ significantly from watermelon varietyNUN 31813 WMW in the distinguishing characteristics above.

Similarity and differences between two different plant lines orvarieties can be determined by comparing the number of morphologicaland/or physiological characteristics that are the same (i.e.,statistically not significantly different) or that are different (i.e.,statistically significantly different) between the two plant lines orvarieties using plants grown under the same environmental conditions. Anumerical characteristic is considered to be “the same” when the valuefor a numeric characteristic is not significantly different at the 1%(p<0.01) or 5% (p<0.05) significance level, using T-test, a standardmethod known to the skilled person. A non-numerical or “degree” or“type” characteristic is considered “the same” when the values have thesame “degree” or “type” when scored using USDA and/or UPOV descriptors,if the plants are grown under the same environmental conditions.

In one aspect, a statistical analysis of the quantitativecharacteristics showing the degree of significance may be provided.Statistical significance is the likelihood that a relationship betweentwo or more variables is caused by something other than chance, i.e.,that the differences in the means for quantitative characteristics ofthe plant of watermelon variety NUN 31813 WMW and the Reference Varietyare significant due to chance. For the purpose of proving differences ordistinction between watermelon variety NUN 31813 WMW and the ReferenceVariety, a p-value of 5% or 0.05 or lower is considered statisticallysignificant. This means that there is only a 5% probability that theobserved result could have happened just by chance or random variation.

The statistical analysis is drawn from a small sample of at least 15plants or plant parts of watermelon variety NUN 31813 WMW and theReference Variety. Statistical points or parameters such as mean,minimum, median, maximum, and standard deviation are collected from thesample data to analyze where the average is, how varied the data set is,and whether the data is skewed. For the purpose of determining whetherthe result of the data set is statistically significant, a T-Test isused, a statistical tool for proving significance in the means of thetwo groups (e.g., watermelon variety NUN 31813 WMW and the ReferenceVariety) at 5% significance level (a p-value of 5% or 0.05).

“Variety” or “cultivar” means a plant grouping within a single botanicaltaxon of the lowest rank.

A “plant line” is, for example, a breeding line which can be used todevelop one or more varieties. A breeding line is typically highlyhomozygous.

“Harvested seeds” refer to seeds harvested from a line or variety, e.g.,produced after self-fertilization or cross-fertilization and collected.

“Hybrid variety” or “F1 hybrid” refers to the seeds harvested fromcrossing two inbred (nearly homozygous) parental lines. For example, thefemale parent is pollinated with pollen of the male parent to producehybrid (F1) seeds on the female parent.

“Locus” (plural loci) refers to the specific location, place or site ofa DNA sequence on a chromosome, where, for example, a gene or geneticmarker is found. A locus may confer a specific trait.

“Allele” refers to one or more alternative forms of a gene locus. All ofthese loci relate to one trait. Sometimes, different alleles can resultin different observable phenotypic traits, such as differentpigmentation. However, many variations at the genetic level result inlittle or no observable variation. If a multicellular organism has twosets of chromosomes, i.e., diploid, these chromosomes are referred to ashomologous chromosomes, i.e., diploid. Diploid organisms have one copyof each gene (and therefore one allele) on each chromosome. If bothalleles are the same, they are homozygotes. If the alleles aredifferent, they are heterozygotes.

“Genotype” refers to the genetic composition of a cell or organism.

“Phenotype” refers to the detectable characteristic of a plant, cell, ororganism, which characteristics are the manifestation of geneexpression.

“Haploid” refers to a cell or organism having one set of the two sets ofchromosomes in a diploid.

“Diploid” refers to a plant, a vegetative plant part(s), or seed which adiploid plant can be grown, having two sets of chromosomes, designatedherein as 2n.

“Triploid” refers to a plant, a vegetative plant part(s), or seed whicha diploid plant can be grown, having three sets of chromosomes,designated herein as 3n.

“Tetraploid” refers to a plant, a vegetative plant part(s), or seedwhich a diploid plant can be grown, having four sets of chromosomes,designated herein as 4n.

“Polyploid” refers to a plant, a vegetative plant part(s), or seed whicha diploid plant can be grown, having three or more complete sets ofchromosomes.

“Pollenizer plant” or “pollinizer” refers to the (inbred or hybrid)diploid plant, or parts thereof (e.g., its pollen or scion), suitable aspollinizer for inducing fruit set on triploid plants. A pollinizer plantis, thus, able to lead to good fruit set (and good triploid fruit yield)of triploid plants, by producing an appropriate amount of pollen at theappropriate day-time and for an appropriate period of time.

“Female parent” or “tetraploid parent” refers to the plant which ispollinated with pollen of male parent, leading to the production offruits containing triploid seeds. The female parent is optionally isinbred so that it is nearly homozygous and stable.

“Male parent” refers to the pollinizer plant used as male parent forinducing fruit set and seed production on a tetraploid female parent,resulting in F1 hybrid triploid seeds. Optionally, one or both the maleparent and the female parent are inbred. If both male and female parentare inbred, i.e., each parent is nearly homozygous and stable, theresulting hybrid triploid will also be genetically uniform and stable.

“Hybrid triploid plant” or “F1 triploid plant” is a triploid plant grownfrom hybrid, triploid seed obtained from cross fertilizing a malediploid parent with a female tetraploid parent.

“Seedless fruit” are triploid fruit which contain no mature seeds. Thefruit may contain one or more small, edible, white ovules.

“Scion” refers to a part of the plant attached to the rootstock. Thisplant is selected for its stems, leaves, flowers, or fruits. The scioncontains the desired genes to be duplicated in future production by thestock/scion plant and may produce the desired watermelon fruit.

“Rootstock” or “stock” refers to the plant selected for its root system,in particular for the resistance of the roots to diseases or stress(e.g., heat, cold, salinity etc.). Generally, the quality of the fruitof the plant providing the rootstock is less important. It is noted thatduring the grafting process, the rootstock root system may be removed,which later grows back to develop a functional root system of thegrafted seedling. Thus, when referring to the rootstock during thegrafting method, this rootstock may be with or without the root system.When referring to the rootstock of the grafted seedlings or plants, there-grown root system is encompassed.

“Stock/scion” or “grafted plant” refers to a watermelon plant comprisinga rootstock from one plant grafted to a scion from another plant.

“Grafting” refers to the method of joining of (genetically) differentplant parts, especially scions and rootstocks, together so that theygrow as a single plant. A grafted seedling or a grafted plant is aseedling or plant (produced by grafting) consisting of such differentplant parts and which grows as one plant.

A “non-grafted” watermelon seedling or plant refers to a seedling orplant grown from a seed (without grafting).

A “single grafted” watermelon seedling or “single grafted” watermelonplant refers to a grafted seedling or plant consisting of a singlewatermelon scion (e.g., triploid watermelon scion or a diploidwatermelon scion) joined with a genetically different rootstock such asa gourd or squash rootstock, another watermelon rootstock, or atransgenic rootstock, etc.

A “double grafted” watermelon seedling or a “double grafted” watermelonplant is herein grafted seedling or plant comprising two watermelonscions grafted onto a single rootstock. In one aspect, two geneticallydifferent watermelon scions, namely a triploid watermelon scion and adiploid watermelon scion, are grafted onto a genetically differentrootstock, such as a gourd or squash rootstock, another watermelonrootstock, or a transgenic rootstock, etc. in another aspect, twotriploid watermelon scions, or two diploid watermelon scions, aregrafted onto a genetically different rootstock, such as a gourd orsquash rootstock, another watermelon rootstock, or a transgenicrootstock, etc.

A “transplant” or ‘seedling transplant’ refers to a watermelon seedlingwhich is at a developmental stage and condition so that it can betransplanted into the field or greenhouse for growth, fruit productionand harvest. The word transplant or seedling transplant can thus,encompass single-grafted, double-grafted, or non-grafted seedlings.

“Interplanting” refers to the combination of two or more type of seedsand/or transplants sown or planted (or transplanted) on the same field,especially the sowing and/or planting (or transplanting) of pollenizersin the same field as triploid hybrid plants (for seedless fruitproduction on the triploid plants and diploid fruit production on thepollinizer plants). For example, the pollinizer may either be planted inseparate rows or interplanted with the triploid plants in the same row(e.g., in hills within each row). Pollenizers may also be planted inbetween rows of triploids. Also, seeds of pollenizers and triploidhybrids may be mixed prior to seedling, resulting in random seeding. Thetransplants of the triploid hybrid plants and/or pollinizer plants mayalso comprise a rootstock of a different plant. Suitable rootstocks areknown in the art. Watermelon plants with a different rootstock arereferred to as “grafted.”

“Planting” or “planted” refers to seeding (direct sowing) ortransplanting seedlings (plantlets) into a field by machine or hand.

The term “traditional breeding techniques” encompasses herein crossing,selfing, selection, doubled haploid production, embryo rescue,protoplast fusion, marker assisted selection, mutation breeding etc. asknown to the breeder (i.e., methods other than geneticmodification/transformation/transgenic methods), by which, for example,a genetically heritable trait can be transferred from one watermelonline or variety to another.

“Tissue culture” or “cell culture” refers to a composition comprisingisolated cells of the same or a different type or a collection of suchcells organized into parts of a plant. Tissue culture of various tissuesof watermelon and regeneration of plants therefrom is well known andwidely published (see, e.g., Compton et al., Plant Cell, Tissue andOrgan Culture 77: 231-243, 2004). Similarly, methods for preparing a“tissue culture” or “cell culture” are well known in the art.

“Regeneration” refers to the development of a plant from cell culture ortissue culture or vegetative propagation.

“Vegetative propagation,” “vegetative reproduction,” or “clonalpropagation” are used interchangeably herein and mean a method of takinga plant part and inducing or allowing that plant part to form at leastroots, and also refer to the plant or plantlet obtained by that method.Optionally, the vegetative propagation is grown into a mature plant. Theskilled person is aware of what plant parts are suitable for use in themethod.

“Crossing” refers to the mating of two parent plants. The termencompasses “cross-pollination” and “selfing”.

“Selfing” refers to self-pollination of a plant, i.e., the transfer ofpollen from the anther to the stigma of the same plant.

“Cross-pollination” refers to the fertilization by the union of twogametes from different plants.

“Backcrossing” is a traditional breeding technique used to introduce atrait into a plant line or variety. The plant containing the trait iscalled the donor plant and the plant into which the trait is transferredis called the recurrent parent. An initial cross is made between thedonor parent and the recurrent parent to produce a progeny plant.Progeny plants which have the trait are then crossed to the recurrentparent. After several generations of backcrossing and/or selfing therecurrent parent comprises the trait of the donor. The plant generatedin this way may be referred to as a “single trait converted plant”. Thetechnique can also be used on a parental line of a hybrid.

“Progeny” as used herein refers to a plant obtained from a plantdesignated NUN 31813 WMW. A progeny may be obtained by regeneration ofcell culture or tissue culture or parts of a plant of said variety orselfing of a plant of said variety or by producing seeds of a plant ofsaid variety. In further aspects, progeny may also encompass plantsobtained from crossing of at least one plant of said variety withanother watermelon plant of the same variety or another variety or line,or with wild watermelon plants. A progeny may comprise a mutation or atransgene. A “first generation progeny” is the progeny directly derivedfrom, obtained from, or derivable from the parent plant by, e.g.,traditional breeding methods (selfing and/or cross-pollinating) orregeneration (optionally combined with transformation or mutation).Thus, a plant of variety NUN 31813 WMW is the male parent, the femaleparent or both of a first generation progeny of watermelon variety NUN31813 WMW. Progeny may have all the physiological and morphologicalcharacteristics of variety NUN 31813 WMW, when grown under the sameenvironmental conditions. Using methods such as backcrossing, recurrentselection, mutation or transformation, one or more specificcharacteristics may be introduced into said variety, to provide or aplant comprising all but 1, 2, or 3 of the morphological andphysiological characteristics of variety NUN 31813 WMW.

The terms “gene converted” or “conversion plant” or “single locusconverted plant” in this context refer to watermelon plants which aredeveloped by traditional breeding techniques, e.g., backcrossing or viagenetic engineering or through mutation breeding, wherein essentiallyall of the desired morphological and physiological characteristics ofthe parent variety or line are recovered, in addition to the one or morecharacteristics introduced into the parent via e.g., the backcrossingtechnique (optionally including reverse breeding or reverse synthesis ofbreeding lines). It is understood that not only the addition of afurther characteristic (e.g., addition of gene conferring a furthercharacteristic, such as a disease resistance gene), but also thereplacement/modification of an existing characteristic by a differentcharacteristic is encompassed herein (e.g., mutant allele of a gene canmodify the phenotype of a characteristic).

Likewise, a “Single Locus Converted (Conversion) Plant” refers to plantsdeveloped by plant breeding techniques comprising or consisting ofmutation and/or by genetic transformation and/or by traditional breedingtechniques, such as backcrossing, wherein essentially all of the desiredmorphological and physiological characteristics of a watermelon varietyare recovered in addition to the characteristics of the single locushaving been transferred into the variety via the abovementionedtechnique, or wherein the morphological and physiologicalcharacteristics of the variety has been replaced/modified in thevariety. In case of a hybrid, the gene may be introduced in the male orfemale parental line.

“Transgene” or “chimeric gene” refers to a genetic locus comprising aDNA sequence which has been introduced into the genome of the plant bytransformation. A plant comprising a transgene stably integrated intoits genome is referred to as “transgenic plant.”

As used herein, the terms “resistance” and “tolerance” are usedinterchangeably to describe plants that show no symptoms orsignificantly reduced symptoms to a specified biotic pest, pathogen,abiotic influence or environmental condition compared to a susceptibleplant. These terms are optionally also used to describe plants showingsome symptoms but that are still able to produce marketable product withan acceptable yield.

“Average” refers herein to the arithmetic mean.

The term “mean” refers to the arithmetic mean of several measurements.The skilled person understands that the appearance of a plant depends tosome extent on the growing conditions of said plant. The mean, if notindicated otherwise within this application, refers to the arithmeticmean of measurements on at least 15 different, randomly selected plantsof a variety or line.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE DISCLOSURE

The disclosure relates to a plant of variety NUN 31813 WMW, wherein arepresentative sample of seeds of said variety has been deposited underthe Budapest Treaty, with Accession number NCIMB ______. NUN 31813 is atriploid, round small, crimson sweet type watermelon variety and issuitable for growing in the open field. Watermelon variety NUN 31813 WMWhas small pips, firm flesh and has low percentage of hollow heart.

The disclosure further relates to a watermelon variety NUN 31813 WMW,which when compared to its Reference Variety has the followingdistinguishing characteristics as shown in Table 3: 1) round small fruittype; 2) thinner stem at second node; 3) shorter mature leaf; 4)stronger blade lobing; 5) weaker blade blistering; 6) round mature fruitshape; 7) shorter mature fruit; 8) smaller fruit; 9) lighter maturefruit; 10) darker yellow green mature fruit primary color; 11) darkergreen mature fruit secondary color; 12) broad elliptic mature fruitshape in longitudinal section; 13) only one colored pattern of stripes;14) broad to very broad stripes; 15) shorter peduncle; 16) thinnerpeduncle; 17) thinner rind at side; 18) thinner rind at stem end; and19) Fusarium oxysporum f. sp. niveum Race 0, when determined at 5%significance level for numerical characteristics and determined by typeor degree for non-numerical characteristics for plants grown under thesame environmental conditions. Also encompassed are parts of that plant.

In one aspect, the plant of variety NUN 31813 WMW or a progeny plantthereof, comprises all of the following morphological and/orphysiological characteristics (i.e., average values of numericalcharacteristics, as indicated on the USDA Objective description ofvariety—watermelon (unless indicated otherwise)) as shown in Tables 1-2,where the numerical characteristics are determined at the 5%significance level for plants and determined by type or degree fornon-numerical characteristics for plants grown under the sameenvironmental conditions. A part of this plant is also provided.

In another aspect, watermelon variety NUN 31813 WMW, or a part thereof,or a progeny thereof, comprises intermediate resistance to Fusariumoxysporum f. sp. niveum Race 0, Fusarium oxysporum f. s.p niveum Race 1,and Colletotrichum lagenarium Race 1, measured according to UPOVstandards described in TG142/5.

The disclosure further provides a watermelon plant which does not differfrom the physiological and morphological characteristics of the plant ofvariety NUN 31813 WMW as determined at the 1%, 2%, 3%, 4%, or 5%significance level when grown under the same environmental conditions.In a particular aspect, the plants are measured in the same trial (e.g.,the trial is conducted as recommended by the USDA or UPOV). Thedisclosure also comprises a part of said plant, preferably a fruit orpart thereof.

The morphological and/or physiological differences between two differentindividual plants described herein (e.g., between watermelon variety NUN31813 WMW and a progeny thereof) or between a plant of variety NUN 31813WMW or progeny of said variety, or a plant having all, or all but 1, 2,or 3, of the physiological and morphological characteristics of varietyNUN 31813 WMW (or all, or all but 1, 2, or 3 of the characteristics aslisted in Tables 1-2) and another known variety can easily beestablished by growing said variety next to each other (in the samefield, under the same environmental conditions), preferably in severallocations which are suitable for said watermelon cultivation, andmeasuring the morphological and physiological characteristics of arepresentative number of plants (e.g., to calculate an average value andto determine the variation range/uniformity within the variety). Forexample, trials can be carried out in Acampo Calif., USA (N 38 degrees07′261″/W 121 degrees 18′ 807″, USA), whereby various characteristics,for example, fruit type, maturity category, ploidy, plant sex form, leafshape, leaf color, lobing, flower color, fruit shape, average fruitweight, fruit color, stripes, rind texture, flesh texture, flesh color,% soluble solids of juice, penetrometer resistance reading, diseaseresistance, and insect resistance can be measured and directly comparedfor species of watermelon.

Also, at-harvest and/or post-harvest characteristics of fruits can becompared, such as cold storage holding quality, post-harvest fleshfirmness, and Brix can be measured using known methods. (Fruit) Fleshfirmness can, for example, be measured using a penetrometer, e.g. byinserting a probe into the fruit flesh and determining the insertionforce, or by other methods. Fruit flesh firmness can for example bemeasured using a “FT 327 Penetrometer”, available from QA Supplies LLC,1185 Pineridge Road, Norfolk, Va. 23502.

Thus, the disclosure comprises watermelon plant having one, two or threephysiological and/or morphological characteristics which are differentfrom those of the plant of variety NUN 31813 WMW and which otherwise hasall the physiological and morphological characteristics of the plant ofvariety NUN 31813 WMW, when determined (e.g., at the 5% significancelevel for quantitative characteristics or determined by type fornon-quantitative characteristics) for plants grown under the sameenvironmental conditions. In one aspect, the different characteristic(s)is/are a result of breeding with watermelon variety NUN 31813 WMW andselection of a progeny plant comprising one, two, or threecharacteristics which are different than in watermelon variety NUN 31813WMW. In another aspect, the different characteristic is the result of amutation (e.g., spontaneous mutation of a human induced mutationthrough, e.g., targeted mutagenesis or traditional mutagenesis such aschemically or radiation induced mutagenesis) or it is a result oftransformation.

The disclosure also relates to a seed of watermelon variety NUN 31813WMW, wherein a representative sample of said seed has been depositedunder the Budapest Treaty, with Accession number NCIMB ______.

In another aspect, a seed of hybrid variety NUN 31813 WMW is obtainableby crossing the male parent of watermelon variety NUN 31813 WMW with thefemale parent of watermelon variety NUN 31813 WMW and harvesting theseeds produced on the female parent. The resultant seeds of said varietycan be grown to produce plants of said variety.

In another aspect, the disclosure provides a plant grown from a seed ofwatermelon variety NUN 31813 WMW and plant part thereof.

The disclosure also provides a watermelon fruit produced on a plantgrown from a seed of watermelon variety NUN 31813 WMW.

In another aspect, the disclosure provides for a watermelon plant partof variety NUN 31813 WMW, preferably a fruit or part thereof, arepresentative sample of seed from said variety has been deposited underthe Budapest Treaty, with Accession number NCIMB ______.

Also provided is a plant of variety NUN 31813 WMW, or a fruit or otherplant part thereof, produced from a seed, wherein a representativesample of said seeds has been deposited under the Budapest Treaty, withAccession Number NCIMB ______.

Also provided is a plant part obtained from variety NUN 31813 WMW,wherein said plant part is a fruit, a harvested fruit, a part of afruit, a leaf, a part of a leaf, pollen, an ovule, a cell, a petiole, ashoot or a part thereof, a stem or a part thereof, a root or a partthereof, a root tip, a cutting, a seed, a part of a seed, seed coat oranother maternal tissue which is part of a seed grown on said variety, ahypocotyl, a cotyledon, a scion, a stock, a rootstock, a pistil, ananther, and a flower or a part thereof. Such plant parts may be suitablefor sexual reproduction (e.g., a pollen, a flower, an ovary, an ovule,an embryo, etc.), vegetative reproduction (e.g., a cutting, a root, astem, a cell, a protoplast, a leaf, a cotyledon, a meristem, etc.) ortissue culture (e.g., a leaf, a pollen, an embryo, a cotyledon, ahypocotyl, a cell, a root, a root tip, an anther, a flower, a seed, astem, etc.). Fruits are particularly important plant parts. Fruits maybe parthenocarpic, or seedless, or contain immature or nonviable seeds,or contain viable seeds.

In a further aspect, the plant part obtained from variety NUN 31813 WMWis a cell, optionally a cell in a cell or tissue culture. That cell maybe grown into a plant of variety NUN 31813 WMW. A part of variety NUN31813 WMW (or of a progeny of that variety or of a plant having allphysiological and/or morphological characteristics but one, two or threeof watermelon variety NUN 31813 WMW) further encompasses any cells,tissues, organs obtainable from the seedlings or plants in any stage ofmaturity.

The disclosure also provides a tissue or cell culture comprising cellsof watermelon variety NUN 31813 WMW. Such a tissue culture can, forexample, be grown on plates or in liquid culture, or be frozen for longterm storage. The cells of watermelon variety NUN 31813 WMW used tostart the culture can be selected from any plant part suitable forvegetative reproduction, or in a particular aspect can be cells of anembryo, a meristem, a cotyledon, a hypocotyl, pollen, a leaf, an anther,a root, a root tip, a pistil, a petiole, a flower, a fruit, a seed, or astem. In another particular aspect, the tissue culture does not containsomaclonal variation or has reduced somaclonal variation. The skilledperson is familiar with methods to reduce or prevent somaclonalvariation, including regular re-initiation.

In one aspect, the disclosure provides a watermelon plant regeneratedfrom the tissue or cell culture of watermelon variety NUN 31813 WMW,wherein the regenerated plant is not significantly different fromwatermelon variety NUN 31813 WMW in all, or all but one, two, or three,of the physiological and morphological characteristics, e.g., determinedat the 5% significance level for numerical characteristics anddetermined by type or degree for non-numerical characteristics whengrown under the same environmental conditions. Optionally, the plant hasone, two, or three the physiological and morphological characteristicsthat are affected by a mutation or by transformation. In another aspect,the disclosure provides a watermelon plant regenerated from the tissueor cell culture of variety NUN 31813 WMW, wherein the plant has all ofthe physiological and morphological characteristics of said variety,e.g., determined at the 5% significance level for numericalcharacteristics and determined by type or degree for non-numericalcharacteristics when grown under the same environmental conditions.Similarity or difference of a characteristic is determined by measuringthat characteristics on a representative number of plants grown underthe same environmental conditions, determining whether type/degreecharacteristics are the same and determining whether numericalcharacteristics are different at the 5% significance level.

Watermelon variety NUN 31813 WMW, or its progeny, or a plant having allphysiological and/or morphological characteristics but one, two or threewhich are different from those of variety NUN 31813 WMW, can also bereproduced using vegetative reproduction methods. Therefore, thedisclosure provides for a method of producing a plant, or a plant part,of variety NUN 31813 WMW, comprising vegetative propagation of saidvariety. Vegetative propagation comprises regenerating a whole plantfrom a plant part of variety NUN 31813 WMW or from a progeny or from ora plant having all physiological and/or morphological characteristics ofsaid variety but one, two or three different characteristics, such as acutting, a cell culture, or a tissue culture.

The disclosure also provides methods of vegetatively propagating a partof the plant of variety NUN 31813 WMW. In certain aspects, the methodcomprises: (a) cultivating tissue or cells capable of being propagatedfrom NUN 31813 WMW to obtain proliferated shoots; and (b) rooting saidproliferated shoots, to obtain rooted plantlets. Steps (a) and (b) mayalso be reversed, i.e., first cultivating said tissue to obtain rootsand then cultivating the tissue to obtain shoots, thereby obtainingrooted plantlets. The rooted plantlets may then be further grown, toobtain plants. In one embodiment, the method further comprises step (c)growing plants from said rooted plantlets. Therefore, the method alsocomprises regenerating a whole plant from a part of variety NUN 31813WMW. In a particular aspect, the part of the plant to be propagated is acutting, a cell culture or a tissue culture.

The disclosure also provides for a vegetatively propagated plant ofvariety NUN 31813 WMW (or from progeny of variety NUN 31813 WMW or fromor a plant having all but one, two or three physiological and/ormorphological characteristics of variety NUN 31813 WMW), wherein theplant has all of the morphological and physiological characteristics ofvariety NUN 31813 WMW when the characteristics are determined at the 5%significance level for plants grown under the same conditions. Inanother aspect, the propagated plant has all but one, two or three ofthe morphological and physiological characteristics of variety NUN 31813WMW when the characteristics are determined at the 5% significance levelfor plants grown under the same conditions. A part of said propagatedplant or said propagated plant with one, two or three differences isalso provided. In another aspect, the propagated plant has all or allbut 1, 2, or 3 of the physiological and morphological characteristics ofwatermelon variety NUN 31813 WMW (e.g., as listed in Tables 1-2).

In another aspect, the disclosure provides a method for producing awatermelon plant part, preferably a fruit, comprising growing a plant ofvariety NUN 31813 WMW until it sets at least one fruit, and collectingthe fruit. Preferably, the fruit is collected at harvest maturity. Inanother aspect, the fruit is collected when the seed is ripe. In aparticular aspect, all fruits on a truss can be harvested together. Inanother particular aspect, all fruit on a watermelon plant can beharvested at the same time.

In another aspect, the plant of variety NUN 31813 WMW can be produced byseeding directly in the soil (e.g., the field) or by germinating theseeds in a controlled environment (e.g., greenhouse) and optionally thentransplanting the seedlings into the field (see, e.g.,https://anrcatalog.ucanr.edu/pdf/7213.pdf). Watermelon can also be grownentirely in greenhouses. For example, a seed is sown into a preparedseed bed in a field where the plant remains for its entire life.Alternatively, the seed may be planted through a black plastic mulch.The dark plastic will absorb heat from the sun, warming the soil early.It will also help to conserve moisture during the growing season,controls weed and makes harvesting easier and cleaner. Triploidvarieties should be interplanted with pollenizers to set fruit.

In another aspect, the plant and plant parts of watermelon variety NUN31813 WMW and progeny of said variety are provided, e.g., grown fromseeds, produced by sexual or vegetative reproduction, regenerated fromthe above-described plant parts, or regenerated from cell or tissueculture of the watermelon variety NUN 31813 WMW, in which the reproduced(seed propagated or vegetatively propagated) plant has all of thephysiological and morphological characteristics of watermelon varietyNUN 31813 WMW, e.g., listed in Tables 1-2. In one aspect, said progenyof watermelon variety NUN 31813 WMW can be modified in one, two, orthree characteristics, in which the modification is a result ofmutagenesis or transformation with a transgene.

In another aspect, the disclosure provides a progeny plant of varietyNUN 31813 WMW such as a progeny plant obtained by further breeding ofvariety NUN 31813 WMW. Further breeding with variety NUN 31813 WMWincludes selfing that variety and/or cross-pollinating variety NUN 31813WMW with another watermelon plant one or more times. In particular, thedisclosure provides for a progeny plant that retains all themorphological and physiological characteristics of variety NUN 31813 WMWor, in another aspect, a progeny plant that retains all, or all but one,two, or three, of the morphological and physiological characteristics ofvariety NUN 31813 WMW, optionally all or all but one, two, or three ofthe characteristics as listed in Tables 1-2, e.g., determined at the 5%significance level for numerical characteristics and determined by typeor degree for non-numerical characteristics, when grown under the sameenvironmental conditions. In another aspect, the progeny is a firstgeneration progeny, i.e., the ovule or the pollen (or both) used in thecrossing is an ovule or pollen of watermelon variety NUN 31813 WMW,where the pollen comes from an anther of watermelon variety NUN 31813WMW and the ovule comes from an ovary of watermelon variety NUN 31813WMW. In another aspect, the disclosure provides for a vegetativereproduction of watermelon variety NUN 31813 WMW and a plant having all,or all but 1, 2, or 3 of the physiological and morphologicalcharacteristics of variety NUN 31813 WMW (e.g., as listed in Tables1-2).

In still another aspect, the disclosure provides a method of producing awatermelon plant, comprising crossing a plant of variety NUN 31813 WMWwith a second watermelon plant at least once, allowing seed to developand optionally harvesting said progeny seed. The skilled person canselect progeny from said crossing. Optionally, the progeny (grown fromthe progeny seed) is crossed twice, thrice, or four, five, six or seventimes, and allowed to set seed. In one aspect, the first “crossing”further comprises planting seeds of a first and a second parentwatermelon plant, often in proximity so that pollination will occur; forexample, mediated by insect vectors. Alternatively, pollen can betransferred manually. Where the plant is self-pollinated, pollinationmay occur without the need for direct human intervention other thanplant cultivation. After pollination the plant can produce seed.

The disclosure also provides a method for collecting pollen ofwatermelon variety NUN 31813 WMW, comprising collecting pollen from avariety NUN 31813 WMW plant.

Alternatively, the method comprises growing a watermelon variety NUN31813 WMW plant until at least one flower contains pollen and collectingthe pollen. In a particular aspect, the pollen is collected when it ismature or ripe. A suitable method for collecting pollen comprisescollecting anthers or the part of the anther that contains pollen, forexample, by cutting the anther or the part of the anther off. Pollen canbe collected in a container. Optionally, collected pollen can be used topollinate a watermelon flower.

In yet another aspect, the disclosure provides a method of producing aplant, comprising selfing a watermelon variety NUN 31813 WMW plant oneor more times, and selecting a progeny plant from said selfing. In oneaspect, the progeny plant retains all or all but one, two or three ofthe physiological and morphological characteristics of variety NUN 31813WMW described above when grown under the same environmental conditions.In a different aspect, the progeny plant comprises all of thephysiological and morphological characteristic of variety NUN 31813 WMWof Tables 1-2.

The disclosure also provides a method for developing a watermelon plantin a watermelon breeding program, using variety NUN 31813 WMW, or itsparts as a source of plant breeding material. Suitable plant breedingtechniques are recurrent selection, backcrossing, pedigree breeding,mass selection, mutation breeding and/or genetic marker enhancedselection. In one aspect, the method comprises crossing watermelonvariety NUN 31813 WMW or its progeny, or a plant comprising all but 1,2, or 3 or more of the morphological and physiological characteristicsof variety NUN 31813 WMW (e.g., as listed in Tables 1-2), with adifferent watermelon plant, and wherein one or more offspring of thecrossing are subject to one or more plant breeding techniques: recurrentselection, backcrossing, pedigree breeding, mass selection, mutationbreeding and genetic marker enhanced selection (see, e.g., Vidaysky andCzosnek, (1998) Phytopathology 88(9): 910-4). For breeding methods ingeneral, see, e.g., Principles of Plant Genetics and Breeding, 2007,George Acquaah, Blackwell Publishing, ISBN-13: 978-1-4051-3646-4.

In one aspect, pedigree selection is used as a breeding method fordeveloping a watermelon variety. Pedigree selection is also known as the“Vilmorin System of Selection,” see, e.g., Allard, John Wiley & Sons,Inc., 1999, pp. 64-67. In general, selection is first practiced among F2plants. In the next season, the most desirable F3 lines are firstidentified, then desirable F3 plants within each line are selected. Thefollowing season and in all subsequent generations of inbreeding, themost desirable families are identified first, then desirable lineswithin the selected families are chosen. A family refers to lines thatwere derived from plants selected from the same progeny from thepreceding generation.

Thus, progeny in connection with pedigree selection are either thegeneration (seeds) produced from the first cross (F1) or selfing (51),or any further generation produced by crossing and/or selfing (F2, F3,etc.) and/or backcrossing (BC1, BC2, etc.) one or more selected plantsof the F1 and/or S1 and/or BC1 generation (or plants of any furthergeneration, e.g., F2) with another watermelon plant (and/or with a wildrelative of watermelon). Progeny may have all the physiological andmorphological characteristics of watermelon variety NUN 31813 WMW whengrown under the same environmental conditions and/or progeny may have(be selected for having) one or more of the distinguishingcharacteristics of watermelon variety NUN 31813 WMW.

In yet another aspect, the disclosure provides for a method of producinga new watermelon plant comprising crossing a plant of variety NUN 31813WMW, or a plant comprising all but one, two, or three of themorphological and physiological characteristics of watermelon varietyNUN 31813 WMW (as listed in Tables 1-2), or a progeny plant thereof,either as male or as female parent, with a second watermelon plant (or awild relative of watermelon) one or more times, and/or selfingwatermelon plant variety NUN 31813 WMW, or a progeny plant thereof, oneor more time, and selecting a progeny watermelon plant from saidcrossing and/or selfing. The second watermelon plant may, for example,be a line or variety of the species Citrullus lanatus, or otherCitrullus species or even other Cucurbitacea species.

In a further aspect, watermelon variety NUN 31813 WMW is used in crosseswith other, different, watermelon varieties to produce first generation(F1) watermelon hybrid seeds and plants with superior characteristics.In a particular aspect, the disclosure provides a watermelon seed and aplant produced by crossing a first parent watermelon plant with a secondparent watermelon plant, wherein at least one of the first or secondparent watermelon plant is watermelon variety NUN 31813 WMW. In anotheraspect, the watermelon seed and plant produced are the first filialgeneration (F1) watermelon seed and plants produced by crossing theplant of watermelon variety NUN 31813 WMW with another watermelon plant.

The morphological and physiological characteristics of watermelonvariety NUN 31813 WMW are provided in Tables 1-2, as collected in atrial according to USDA and/or UPOV standards. Encompassed herein isalso a plant obtainable from watermelon variety NUN 31813 WMW (e.g., byselfing and/or crossing and/or backcrossing with said variety and/orprogeny of said variety) comprising all or all but one, two, or three ofthe physiological and morphological characteristics of watermelonvariety NUN 31813 WMW listed in Tables 1-2 (as determined at the 5%significance level for quantitative characteristics or identical fornon-quantitative characteristics) when grown under the sameenvironmental conditions and/or comprising one or more (or all; or allexcept one, two, or three) characteristics when grown under the sameenvironmental conditions. The morphological and/or physiologicalcharacteristics may vary somewhat with variation in the environment(e.g., temperature, light intensity, day length, humidity, soil,fertilizer use, disease vectors), which is why a comparison under thesame environmental conditions is preferred. Colors can best be measuredusing the Royal Horticultural Society (RHS) Chart.

In another aspect, the disclosure provides a method of producing a plantderived from a watermelon variety NUN 31813 WMW, comprising crossing aplant of variety NUN 31813 WMW either as a male or female parent with asecond plant or selfing watermelon variety NUN 31813 WMW or vegetativereproduction of watermelon variety NUN 31813 WMW and collecting seedsfrom said crossing or selfing or regenerating a whole plant from thevegetable cell- or tissue culture. Also provided are seeds and/or plantsobtained by this method. All plants produced using watermelon varietyNUN 31813 WMW as a parent are within the scope of the disclosureincluding plant parts derived from watermelon variety NUN 31813 WMW.

In a further aspect, the method comprises growing a progeny plant of asubsequent generation and crossing the progeny plant of a subsequentgeneration with itself or a second plant and repeating the steps foradditional 3-10 generations to produce a plant derived from watermelonvariety NUN 31813 WMW. The plant derived from watermelon variety NUN31813 WMW may be an inbred line and the aforementioned repeatingcrossing steps may be defined as comprising sufficient inbreeding toproduce the inbred line. By selecting plants having one or moredesirable traits of the line as well as potentially other selectedtraits.

The disclosure provides for methods of producing a plant which retainall the morphological and physiological characteristics of the plantdescribed herein. The disclosure also provides for methods of producinga plant comprising all but 1, 2, or 3 or more of the morphological andphysiological characteristics of watermelon variety NUN 31813 WMW (e.g.,as listed in Tables 1-2), but which are still genetically closelyrelated to said variety. The relatedness can, for example, be determinedby fingerprinting techniques (e.g., making use of isozyme markers and/ormolecular markers such as Single-nucleotide polymorphism (SNP) markers,amplified fragment length polymorphism (AFLP) markers, microsatellites,minisatellites, Random Amplified Polymorphic DNA (RAPD) markers,restriction fragment length polymorphism (RFLP) markers and others). Aplant is “closely related” to variety NUN 31813 WMW if its DNAfingerprint is at least 80%, 90%, 95% or 98% identical to thefingerprint of said variety. In a particular aspect AFLP markers areused for DNA fingerprinting (see, e.g., Vos et al. 1995, Nucleic AcidResearch 23: 4407-4414). A closely related plant may have a Jaccard'sSimilarity index of at least about 0.8, preferably at least about 0.9,0.95, 0.98 or more (see, e.g., Parvathaneni et al., J. Crop Sci.Biotech. 2011 (March) 14 (1): 39-43). The disclosure also provides aplant obtained or selected by applying these methods on watermelonvariety NUN 31813 WMW. Such a plant may be produced by traditionalbreeding techniques, or mutation or transformation or in another aspect,a plant may simply be identified and selected amongst plants of saidvariety, or progeny of said variety, e.g., by identifying a variant ofwatermelon variety NUN 31813 WMW, or within progeny of said variety,which variant differs from the variety described herein watermelon inone, two or three of the morphological and/or physiologicalcharacteristics (e.g., characteristics listed in Tables 1-2). In oneaspect, the disclosure provides a watermelon plant having a Jaccard'sSimilarity index with watermelon variety NUN 31813 WMW of at least 0.8,e.g., at least 0.85, 0.9, 0.95, 0.98 or even at least 0.99.

In some aspects, the disclosure provides a watermelon plant comprisinggenomic DNA having at least 95%, 96%, 97%, 98% or 99% sequence identitycompared to the genomic DNA sequence of a plant of variety NUN 31813 WMWas deposited under Accession Number NCIMB ______. In some aspects, thewatermelon plant further comprises all or all but 1, 2, or 3 of themorphological and physiological characteristics of variety NUN 31813 WMW(e.g., as listed in Tables 1-2). In other aspects, the watermelon plantis a hybrid derived from a seed or plant of variety NUN 31813 WMW. Inother aspects, the watermelon plant further comprises all of thedistinguishing characteristics of a plant of variety NUN 31813 WMW.

For the purpose of this disclosure, the “sequence identity” ofnucleotide sequences, expressed as a percentage, refers to the number ofpositions in the two optimally aligned sequences which have identicalresidues (×100) divided by the number of positions compared. A gap,i.e., a position in the pairwise alignment where a residue is present inone sequence but not in the other, is regarded as a position withnon-identical residues. A pairwise global sequence alignment of twonucleotide sequences is found by aligning the two sequences over theentire length according to the Needleman and Wunsch global alignmentalgorithm described in Needleman and Wunsch, 1970, J. Mol. Biol.48(3):443-53). A full implementation of the Needleman-Wunsch globalalignment algorithm is found in the needle program in The EuropeanMolecular Biology Open Software Suite (see, e.g., EMBOSS, Rice et al.,Trends in Genetics June 2000, vol. 16, No. 6. pp. 276-2′7′7).

In another aspect, the plant of variety NUN 31813 WMW may also bemutated (by e.g., irradiation, chemical mutagenesis, heat treatment,etc.) and mutated seeds or plants may be selected in order to change oneor more characteristics of said variety. Methods such as TILLING(Targeting Induced Local Lesions in Genomes) may be applied topopulations in order to identify mutants.

Similarly, watermelon variety NUN 31813 WMW may be transformed andregenerated, whereby one or more chimeric genes are introduced into thevariety or into a plant comprising all but 1, 2, 3, or more of themorphological and physiological characteristics (e.g., as listed inTables 1-2). Many useful traits can be introduced into watermelonvariety NUN 31813 WMW by e.g., crossing a watermelon variety NUN 31813WMW with a transgenic watermelon plant comprising a desired transgene,as well as by directly introducing a transgene into watermelon varietyNUN 31813 WMW by genetic transformation techniques.

Any pest or disease resistance genes may be introduced into watermelonvariety NUN 31813 WMW, progeny of said variety or into a plantcomprising all but 1, 2, or 3 or more of the morphological andphysiological characteristics of variety NUN 31813 WMW (e.g., as listedin Tables 1-2). Resistance to one or more of the following diseases orpests may be introduced into plants described herein: Colletotrichumorbiculare (Anthracnose), Pseudoperonospora cubensis (Downy Mildew),Fusarium oxysporum f sp. niveum (Fusarium Wilt), Didymella bryoniae(Gummy Stem Blight), Podosphaera xanthii (Powdery Mildew), Verticilliumsp. (Verticillium Wilt), Squash Mosaic Virus, Watermelon Mosaic Virus(WMV), Cucumber Mosaic Virus (CMV), Papaya Ringspot Virus (PRWV-W),Zucchini Yellow Mosaic Virus (ZYMV), Cucurbit Yellow Stunting DisorderVirus (CYSDV), Macrophomina phaseolina (Charcoal Rot), Monosporascuscannonballus (Monosporascus Vine Decline), Sunburn, Root Knot, and/orBemisia tabaci (Silverleaf Whitefly). Other resistance genes, againstpathogenic viruses, fungi, bacteria, nematodes, insects or other pestsmay also be introduced.

Genetic transformation may, therefore, be used to insert a selectedtransgene into the watermelon plants of the disclosure described hereinor may, alternatively, be used for the preparation of transgenicwatermelon plants which can be used as a source of the transgene(s),which can be introduced into watermelon variety NUN 31813 WMW by e.g.,backcrossing. A genetic trait which has been engineered into the genomeof a particular watermelon plant may then be moved into the genome ofanother watermelon plant (e.g., another variety) using traditionalbreeding techniques which are well-known in the art. For example,backcrossing is commonly used to move a transgene from a transformedwatermelon variety into an already developed watermelon variety and theresulting backcross conversion plant will then comprise thetransgene(s).

Any DNA sequences, whether from a different species or from the samespecies, which are inserted into the genome using transformation, arereferred to herein collectively as “transgenes.” A “transgene” alsoencompasses antisense, or sense and antisense sequences capable of genesilencing. Thus, the disclosure also relates to transgenic plants ofwatermelon variety NUN 31813 WMW. In some aspects, a transgenic plant ofwatermelon variety NUN 31813 WMW may contain at least one transgene butcould also contain at least 1, 2, 3, 4, or more transgenes.

Plant transformation involves the construction of an expression vectorwhich will function in plant cells. Such a vector comprises DNAcomprising a gene under control of, or operatively linked to aregulatory element active in plant cells (e.g., promoter). Theexpression vector may contain one or more such operably linkedgene/regulatory element combinations. The vector may be in the form of aplasmid and can be used alone or in combination with other plasmids toprovide transformed watermelon plants using transformation methods toincorporate transgenes into the genetic material of the watermelonplant(s). Transformation can be carried out using standard methods, suchas Agrobacterium tumefaciens mediated transformation, electroporation,biolistics particle delivery system, or microprojectile bombardment,followed by selection of the transformed cells and regeneration intoplants.

Plants can also be genetically engineered, modified, or manipulated toexpress various phenotypes of horticultural interest. Through thetransformation of watermelon, the expression of genes can be altered toenhance disease resistance, insect resistance, herbicide resistance,stress tolerance, horticultural quality, and other traits.Transformation can also be used to insert DNA sequences which control orhelp control male sterility or fertility restoration. DNA sequencesnative to watermelon as well as non-native DNA sequences can betransformed into watermelon and used to alter levels of native ornon-native proteins. Various promoters, targeting sequences, enhancingsequences, and other DNA sequences can be inserted into the genome forthe purpose of altering the expression of proteins. Reduction of thespecific activity of specific genes (also known as gene silencing orgene suppression) is desirable for several aspects of geneticengineering in plants.

Genome editing is another method recently developed to geneticallyengineer plants. Specific modification of chromosomal loci or targetedmutation can be done through sequence-specific nucleases (SSNs) byintroducing a targeted DNA double strand break in the locus to bealtered. Examples of SSNs that have been applied to plants are: fingernucleases (ZFNs), transcription activator-like effector nucleases(TALENs), engineered homing endonucleases or meganucleases, andclustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9 (Cas9), see, e.g., Songstad, et.al., Critical Reviews in Plant Sciences, 2017, 36:1, 1-23.

Thus, the disclosure also provides a method of producing a watermelonplant having a desired trait comprising mutating the plant or plant partof watermelon variety NUN 31813 WMW and selecting a plant comprising thedesired trait, wherein the mutated plant retains all or all but one,two, or three of the morphological and physiological characteristics ofvariety NUN 31813 WMW, and contains the desired trait and wherein arepresentative sample of seed of said watermelon variety has beendeposited under Accession Number NCIMB ______. In a further aspect, thetransformation or mutation confers a trait wherein the trait is yield,storage properties, color, flavor, male sterility, herbicide tolerance,insect resistance, pest resistance, disease resistance, environmentalstress tolerance, modified carbohydrate metabolism, modified proteinmetabolism, or occurs in the intense gene.

The disclosure also provides a method for inducing a mutation inwatermelon variety NUN 31813 WMW comprising:

-   -   a. exposing the seed, plant, plant part, or cell of watermelon        variety NUN 31813 WMW to a mutagenic compound or to radiation,        wherein a representative sample of seed of said watermelon        variety NUN 31813 WMW has been deposited under Accession Number        NCIMB ______;    -   b. selecting the seed, plant, plant part, or cell of watermelon        variety NUN 31813 WMW having a mutation; and    -   c. optionally growing and/or multiplying the seed, plant or        plant part or cell of watermelon variety NUN 31813 WMW having        the mutation.

The disclosure also provides a method of producing a watermelon planthaving a desired trait, wherein the method comprises transforming thewatermelon plant with a transgene that confers the desired trait,wherein the transformed plant otherwise retains all of the physiologicaland morphological characteristics of the plant of variety NUN 31813 WMWand contains the desired trait. Thus, a transgenic watermelon plant isprovided which is produced by the method described above, wherein theplant otherwise has all of the physiological and morphologicalcharacteristics of watermelon variety NUN 31813 WMW and the desiredtrait.

In another aspect, the disclosure provides a method of producing aprogeny of plant of variety NUN 31813 WMW further comprising a desiredtrait, said method comprising transforming the plant of watermelonvariety NUN 31813 WMW with at least one transgene that confers thedesired trait and/or crossing the plant of watermelon variety NUN 31813WMW with a transgenic watermelon plant comprising a desired transgene sothat the genetic material of the progeny that resulted from the crosscontains the desired transgene(s). Also encompassed is the progenyproduced by this method.

A desired trait (e.g., gene(s) conferring pest or disease resistance, ortolerance for protection, etc.) can be introduced into watermelonvariety NUN 31813 WMW, or progeny of said variety, by transforming saidvariety or progeny of said variety with a transgene that confers thedesired trait, wherein the transformed plant retains all or all but one,two or three of the morphological and/or physiological characteristicsof variety NUN 31813 WMW and contains the desired trait. In anotheraspect, the transformation or mutation confers a trait wherein the traitis yield, storage properties, color, flavor, male sterility, herbicidetolerance, insect resistance, pest resistance, disease resistance,environmental stress tolerance, modified carbohydrate metabolism,modified protein metabolism or occurs in the intense gene. In aparticular aspect, the specific transgene may be any known in the art orlisted herein, including, a polynucleotide sequence conferringresistance to imidazolinone, sulfonylurea, glyphosate, glufosinate,triazine, benzonitrile, cyclohexanedione, phenoxy proprionic acid andL-phosphinothricin or a polynucleotide conferring resistanceColletotrichum orbiculare (Anthracnose), Pseudoperonospora cubensis(Downy Mildew), Fusarium oxysporum f. sp. niveum (Fusarium Wilt),Didymella bryoniae (Gummy Stem Blight), Podosphaera xanthii (PowderyMildew), Verticillium sp. (Verticillium Wilt), Squash Mosaic Virus,Watermelon Mosaic Virus (WMV), Cucumber Mosaic Virus (CMV), PapayaRingspot Virus (PRWV-W), Zucchini Yellow Mosaic Virus (ZYMV), CucurbitYellow Stunting Disorder Virus (CYSDV), Macrophomina phaseolina(Charcoal Rot), Monosporascus cannonballus (Monosporascus Vine Decline),Sunburn, Root Knot, and/or Bemisia tabaci (Silverleaf Whitefly). Otherresistance genes, against pathogenic viruses, fungi, bacteria,nematodes, insects or other pests may also be introduced.

By crossing and/or selfing, (one or more) single traits may beintroduced into watermelon variety NUN 31813 WMW (e.g., usingbackcrossing breeding schemes), while retaining the remainingmorphological and physiological characteristics of said variety and/orwhile retaining one or more or all distinguishing characteristics. Asingle trait converted plant may thereby be produced. For example,disease resistance genes may be introduced, genes responsible for one ormore quality traits, yield, etc. Both single genes (e.g., dominant orrecessive) and one or more QTLs (quantitative trait loci) may betransferred into watermelon variety NUN 31813 WMW by breeding with saidvariety.

In another aspect, the disclosure provides a method of introducing asingle locus conversion or single trait conversion or a desired traitinto watermelon variety NUN 31813 WMW, comprising introducing a singlelocus conversion in at least one of the parents of variety NUN 31813WMW; and crossing the converted parent with the other parent of varietyNUN 31813 WMW, to obtain seed of said variety.

In another aspect, the step of introducing a single locus conversion,single trait conversion, or desired trait in at least one of the parentplants comprises:

-   -   a. crossing the parental line of watermelon variety NUN 31813        WMW with a second watermelon plant comprising the single locus        conversion, the single trait conversion or the desired trait;    -   b. selecting F1 progeny plants that contain the single locus        conversion, the single trait conversion or the desired trait;    -   c. crossing said selected progeny plants of step b) with the        parental line of step a), to produce a backcross progeny plant;    -   d. selecting backcross progeny plants comprising the single        locus conversion, the single trait conversion or the desired        trait and otherwise all or all but one, two or three of the        morphological and physiological characteristics the parental        line of step a) to produce selected backcross progeny plants;        and    -   e. optionally repeating steps c) and d) one or more times in        succession to produce selected second, third or fourth or higher        backcross progeny plants comprising the single locus conversion,        the single trait conversion or the desired trait and otherwise        all or all but one, two or three of the morphological and        physiological characteristics the parental line of step a) to        produce selected backcross progeny plants, when grown in the        same environmental conditions.        The disclosure further relates to plants obtained by this        method.

In another aspect, introducing a single locus conversion in at least oneof the parent plants comprises:

-   -   a. obtaining a cell or tissue culture of cells of the parental        line of watermelon variety NUN 31813 WMW;    -   b. genetically transforming or mutating said cells;    -   c. growing the cells into a plant; and    -   d. optionally selecting plants that contain the single locus        conversion, the single trait conversion or the desired trait.

In another aspect, the disclosure provides a method of introducing asingle locus conversion or single trait conversion or a desired traitinto watermelon variety NUN 31813 WMW comprising:

-   -   a. obtaining a combination of a parental lines of watermelon        variety NUN 31813 WMW, optionally through reverse synthesis of        breeding lines;    -   b. introducing a single locus conversion in at least one of the        parents of step a; and    -   c. crossing the converted parent with the other parent of step a        to obtain seed of watermelon variety NUN 31813 WMW.

In another method, the step of introducing a single locus conversion inat least one of the parents comprises genetically transforming ormutating cells the parental line of watermelon variety NUN 31813 WMW;growing the cells into a plant; and optionally selecting plants thatcontain the single locus conversion, the single trait conversion or thedesired trait.

In any of the above methods, where the single locus conversion concernsa trait, the trait may be yield or pest resistance or diseaseresistance. In one aspect, the trait is disease resistance and theresistance is conferred to Colletotrichum orbiculare (Anthracnose),Pseudoperonospora cubensis (Downy Mildew), Fusarium oxysporum f sp.niveum (Fusarium Wilt), Didymella bryoniae (Gummy Stem Blight),Podosphaera xanthii (Powdery Mildew), Verticillium sp. (VerticilliumWilt), Squash Mosaic Virus, Watermelon Mosaic Virus (WMV), CucumberMosaic Virus (CMV), Papaya Ringspot Virus (PRWV-W), Zucchini YellowMosaic Virus (ZYMV), Cucurbit Yellow Stunting Disorder Virus (CYSDV),Macrophomina phaseolina (Charcoal Rot), Monosporascus cannonballus(Monosporascus Vine Decline), Sunburn, Root Knot, and/or Bemisia tabaci(Silverleaf Whitefly). Other resistance genes against pathogenicviruses, fungi, bacteria, nematodes, insects or other pests may also beintroduced.

The disclosure also provides a plant having one, two, or threephysiological and/or morphological characteristics which are differentfrom those of watermelon variety NUN 31813 WMW and which otherwise hasall the physiological and morphological characteristics of said variety,wherein a representative sample of seed of said variety has beendeposited under Accession Number NCIMB ______. In particular, variantswhich differ from watermelon variety NUN 31813 WMW in no, one, two, orthree of the characteristics mentioned in Tables 1-2 are encompassed.

The disclosure also provides a plant comprising at least a first set ofthe chromosomes of watermelon variety NUN 31813 WMW, a sample of seedhas been deposited under Accession Number NCIMB ______, optionallyfurther comprising a single locus conversion. In another aspect, thesingle locus conversion confers a trait wherein the trait is yield,storage, color, flavor, male sterility, herbicide tolerance, insectresistance, pest resistance, disease resistance, environmental stresstolerance, modified carbohydrate metabolism, modified proteinmetabolism, or ripening.

In another aspect, the disclosure provides a haploid plant and/or adoubled haploid plant of variety NUN 31813 WMW, or a plant having allbut one, two, or three physiological and/or morphologicalcharacteristics of variety NUN 31813 WMW, or progeny of any of these.Haploid and doubled haploid (DH) plants can, for example, be produced bycell or tissue culture and chromosome doubling agents and regenerationinto a whole plant. DH production chromosome doubling may be inducedusing known methods, such as colchicine treatment or the like. In oneaspect, the method comprises inducing a cell or tissue culture with achromosome doubling agent and regenerating the cells or tissues into awhole plant.

In another aspect, the disclosure comprises a method for making doubledhaploid cells of watermelon variety NUN 31813 WMW, comprising makingdoubled haploid cells from haploid cells from the plant or plant part ofwatermelon variety NUN 31813 WMW with a chromosome doubling agent suchas colchicine treatment (see, e.g., Nikolova and Niemirowicz-Szczytt(1996) Acta Soc Bot Pol 65:311-317).

In yet another aspect, the disclosure provides for haploid plants and/ordoubled haploid plants derived from watermelon variety NUN 31813 WMWthat, when combined, make a set of parents of variety NUN 31813 WMW. Thehaploid plant and/or the doubled haploid plant of variety NUN 31813 WMWcan be used in a method for generating parental lines of watermelonvariety NUN 31813 WMW.

The disclosure also provides methods for determining the identity ofparental lines of plants described herein, in particular the identity ofthe female line. US2015/0126380, which is hereby incorporated byreference, relates to a non-destructive method for analyzing maternalDNA of a seed. In this method, the DNA is dislodged from the seed coatsurface and can be used to collect information on the genome of thematernal parent of the seed. This method for analyzing maternal DNA of aseed comprises contacting a seed with a fluid to dislodge DNA from theseed coat surface, and analyzing the DNA thus dislodged from the seedcoat surface using methods known in the art. The skilled person is thusable to determine whether a seed has grown on a plant of a plant ofvariety NUN 31813 WMW or is a progeny of said variety, because the seedcoat of the seed is a maternal tissue genetically identical to varietyNUN 31813 WMW. In one aspect, the disclosure relates to a maternaltissue of variety NUN 31813 WMW. In another aspect, the disclosurerelates to a watermelon seed comprising a maternal tissue of variety NUN31813 WMW. In another particular aspect, the disclosure provides amethod of identifying the female parental line of watermelon variety NUN31813 WMW by analyzing the seed coat of a seed of that variety. Inanother aspect, the skilled person can determine whether a seed is grownon watermelon NUN 31813 WMW by analyzing the seed coat or anothermaternal tissue of said seed.

Using methods known in the art such as “reverse synthesis of breedinglines” or “reverse breeding”, it is possible to produce parental linesfor a hybrid plant such as watermelon variety NUN 31813 WMW. A skilledperson can take any individual heterozygous plant (called a“phenotypically superior plant” in Example 2 of US2015/0245570 herebyincorporated by reference in its entirety; watermelon variety NUN 31813WMW is such a plant) and generate a combination of parental lines(reverse breeding parental lines) that, when crossed, produce thevariety NUN 31813 WMW. It is not necessary that the reverse breedingparental lines are identical to the original parental lines. Such newbreeding methods are based on the segregation of individual alleles inthe spores produced by a desired plant and/or in the progeny derivedfrom the self-pollination of that desired plant, and on the subsequentidentification of suitable progeny plants in one generation, or in alimited number of inbred cycles. Such a method is known fromUS2015/0245570 or from Wijnker et al., Nature Protocols Volume: 9,Pages: 761-772 (2014) DOI: doi:10.1038/nprot.2014.049. Thus, thedisclosure provides a method for producing parental lines for a hybridorganism (e.g., watermelon variety NUN 31813 WMW), comprising in oneaspect: a) defining a set of genetic markers present in a heterozygousform (H) in a partially heterozygous starting organism; b) producingdoubled haploid lines from spores of the starting organism; c)genetically characterizing the doubled haploid lines thus obtained forthe said set of genetic markers to determine whether they are present ina first homozygous form (A) or in a second homozygous form (B); and d)selecting at least one pair of doubled haploid lines that havecomplementary alleles for at least a subset of the genetic markers,wherein each member of the pair is suitable as a parental line for thehybrid organism.

In another aspect, the method for producing parental lines for hybridorganisms, e.g., of NUN 31813 WMW, which when crossed reconstitute thegenome of NUN 31813 WMW, comprising:

-   -   a. defining a set of genetic markers that are present in a first        homozygous form (H) in a partially heterozygous starting        organism;    -   b. producing at least one further generation from the starting        organism by self-pollination (e.g., F2 or F3 generation);    -   c. selecting at least one pair of progeny organisms in which at        least one genetic marker from the set is present in a        complementary homozygous forms (B vs. A, or A vs. B); and    -   d. optionally repeating steps b) and c) until at least one pair        of progeny organisms that have complementary alleles for at        least a subset of the genetic markers has been selected as        parental lines for a hybrid.

The disclosure relates to a method of producing a combination ofparental lines of a plant of variety NUN 31813 WMW, comprising makingdoubled haploid cells from haploid cells from said plant or a seed ofthat plant; and optionally crossing these parental lines to produce andcollecting seeds. In another aspect, the disclosure relates to acombination of parental lines produced by this method. In still anotheraspect, the combination of parental lines can be used to produce a seedor plant of variety NUN 31813 WMW when these parental lines are crossed.In still another aspect, the disclosure relates to a combination ofparental lines from which a seed or plant having all physiologicaland/or morphological characteristics of variety NUN 31813 WMW (when thecharacteristics are determined at the 5% significance level for plantsgrown under the same environmental conditions).

The disclosure also provides a combination of parental lines which, whencrossed, produce a seed or plant having all physiological and/ormorphological characteristics of watermelon variety NUN 31813 WMW butone, two or three characteristics which are different (when grown underthe same environmental conditions), as well as a seed or plant havingall physiological and/or morphological characteristics of variety NUN31813 WMW but one, two or three characteristics which are different(when the characteristics are determined at the 5% significance levelfor plants grown under the same environmental conditions).

In another aspect, a combination of a male and a female parental line ofwatermelon variety NUN 31813 WMW can be generated by methods describedherein, for example, through reverse synthesis of breeding lines.

In another aspect, the disclosure provides a method of determining thegenotype of a plant described herein comprising detecting in the genome(e.g., a sample of nucleic acids) of the plant at least a firstpolymorphism or an allele. The skilled person is familiar with manysuitable methods of genotyping, detecting a polymorphism or detecting anallele including SNP (Single Nucleotide Polymorphism) genotyping,restriction fragment length polymorphism identification (RFLP) ofgenomic DNA, random amplified polymorphic detection (RAPD) of genomicDNA, amplified fragment length polymorphism detection (AFLP), polymerasechain reaction (PCR), DNA sequencing, allele specific oligonucleotide(ASO) probes, and hybridization to DNA microarrays or beads.Alternatively, the entire genome could be sequenced. The method may, incertain embodiments, comprise detecting a plurality of polymorphisms inthe genome of the plant, for example by obtaining a sample of nucleicacid from a plant and detecting in said nucleic acids a plurality ofpolymorphisms. The method may further comprise storing the results ofthe step of detecting the plurality of polymorphisms on a computerreadable medium.

Also provided is a plant part of variety NUN 31813 WMW (or from progenyof said variety or from a plant having all physiological and/ormorphological characteristics but one, two, or three which are differentfrom those of said variety) or from a vegetatively propagated plant ofvariety NUN 31813 WMW (or from its progeny or from a plant having all orall but one, two, or three of the physiological and morphologicalcharacteristics which are different from those of watermelon variety NUN31813 WMW), wherein said plant part is a fruit, a harvested fruit, apart of a fruit, a leaf, a part of a leaf, pollen, an ovule, a cell, apetiole, a shoot or a part thereof, a stem or a part thereof, a root ora part thereof, a root tip, a cutting, a seed, a part of a seed, seedcoat or another maternal tissue which is part of a seed grown on saidvariety, a hypocotyl, cotyledon, a scion, a stock, a rootstock, apistil, an anther, and a flower or a part thereof.

A part of the plant of variety NUN 31813 WMW (or of progeny of saidvariety or of a plant having all of the physiological and morphologicalcharacteristics but one, two, or three which are different from those ofsaid variety) encompasses any cells, tissues, organs obtainable from theseedlings or plants, such as but not limited to: a watermelon fruit or apart thereof, a cutting, a hypocotyl, a cotyledon, seed coat, or pollen.

Such a plant part of variety NUN 31813 WMW can be stored and/orprocessed further. The disclosure thus also provides for a food or feedproduct comprising one or more of such parts from watermelon variety NUN31813 WMW or from progeny of said variety, or from a derived variety,such as a plant having all but one, two, or three physiological and/ormorphological characteristics of variety NUN 31813 WMW. Preferably, theplant part is a watermelon fruit or part thereof and/or an extract froma fruit or another plant part described herein comprising at least onecell of watermelon variety NUN 31813 WMW. The food or feed product maybe fresh or processed, e.g., dried, grinded, powdered, pickled, chopped,cooked, roasted, in a sauce, in a sandwich, pasted, puréed orconcentrated, juiced, pickled, canned, steamed, boiled, fried, blanchedand/or frozen, etc.

In another aspect, the disclosure provides for a watermelon fruit ofvariety NUN 31813 WMW, or a part of a fruit of said variety. The fruitcan be in any stage of maturity, for example, immature or mature. Inanother aspect, the disclosure provides for a container comprising orconsisting of a plurality of harvested watermelon fruits or parts offruits of said variety, or fruits of progeny thereof, or fruits of aderived variety.

Marketable fruits are generally sorted by size and quality afterharvest. Alternatively, the fruits can be sorted by expected shelf life,pH or Brix.

In another aspect, the plant, plant part or seed of watermelon varietyNUN 31813 WMW is inside a container, for example, containers such ascans, boxes, crates, bags, cartons, Modified Atmosphere Packaging, films(e.g., biodegradable films), etc. comprising a plant or a plant part(fresh and/or processed) or a seed of watermelon variety NUN 31813 WMW.In a particular aspect, the container comprises a plurality of seeds, ora plurality of plant parts of watermelon variety NUN 31813 WMW.

In another aspect, a seed or a plurality of seeds of said variety arepackaged into a container of any size or type (e.g., bags, cartons,cans, etc.). The seed may be disinfected, primed and/or treated withvarious compounds, such as seed coatings or crop protection compounds.The seed produces a plant of variety NUN 31813 WMW.

Watermelons may also be grown for use as rootstocks (stocks) or scions.Typically, different types of watermelons are grafted to enhance diseaseresistance, which is usually conferred by the rootstock, while retainingthe horticultural qualities usually conferred by the scion. It is notuncommon for grafting to occur between cultivated watermelon varietiesand related watermelon species. Methods of grafting and vegetativepropagation are well-known in the art.

In another aspect, the disclosure provides to a plant comprising arootstock or scion of watermelon variety NUN 31813 WMW.

All documents (e.g., patent publications) are herein incorporated byreference in their entirety, including the following cited references:

-   Naktuinbouw, Calibration Manual: DUS Test for Watermelon (Citrillus    lanatus), 2017.-   UPOV, Guidelines for the Conduct of Tests for Distinctness,    Uniformity and Stability, TG142/5, world-wide web at    upov.int/edocs/tgdocs/en/tg142.pdf.-   US Department of Agriculture, Objective Description of    Variety—Watermelon (Citrullus lanatus)”, world-wide web at    ams.usda.gov/under services/plant-variety-protection/pvpo-c-forms    under watermelon.-   Compton, M., et al., “Use of Tissue Culture and Biotechnology for    the Genetic Improvement of Watermelon”, Plant Cell, Tissue and Organ    Culture, 2004, vol. 77, pp. 231-243.-   Eigsti, O., “About our Cover”, HortScience, 1971, vol. 6, pp. 1-2.-   Hayata, Y., et. al., “Synthetic    Cytokinin-1-(2=chloro=4=pyridyl)-3-phenylurea (CPPU)-Promotes Fruit    Set and Induces Parthenocarpy in Watermelon”, Society of    Horticultural Science, 1995, vol. 120(6), pp. 997-1000.-   Kihara, H., “Triploid Watermelon”, Proceedings of American Society    for Horticultural Science, 1951, vol. 58, pp. 217-230.-   Moussa, H., et. al., “Parthenocarpy of Watermelon Cultivars Induced    by γ-Irradiation”, Russian Journal of Plant Physiology, 2010, vol.    57, no. 4, pp. 574-581.-   Parvathaneni, R. K., et al., “Fingerprinting in Cucumber and Melon    (Cucumis spp.) genotypes Using Morphological and ISSR Markers”,    Journal of Crop Science and Biotechnology, 2011, vol. 14, no. 1, pp.    39-43. DOI No. 10.1007/s12892-010-0080-1.-   Rice, P., et al., “EMBOSS: The European Molecular Biology Open    Software Suite”, Trends in Genetics, 2000, vol. 16, Issue 6. pp.    276-277.-   Vidaysky, F., et. al., “Tomato Breeding Lines Resistant and Tolerant    to Tomato Yellow Leaf Curl Virus Issued from Lycopersicum hirsutum”,    The American Phytopathology Society, 1998, vol. 88, no. 9, pp.    910-914.-   Vos, P., et al., “AFLP: A New Technique for DNA Fingerprinting”,    Nucleic Acids Research, 1995, vol. 23(21), pp. 4407-4414.-   Wijnker, E., et al., “Hybrid Recreation by Reverse breeding in    Arabidopsis thaliana”, Nature Protocols, 2014, vol. 9, pp. 761-772.    DOI: doi: 10.1038/nprot.2014.049-   U.S. Pat. No. 8,418,637-   US2015/0126380-   US2015/0245570-   US2006/0168701

Development of Watermelon Variety NUN 31813 WMW

The hybrid NUN 31813 WMW was developed from a male and femaleproprietary inbred line of Nunhems. The female and male parents werecrossed to produce hybrid (F1) seeds of watermelon variety NUN 31813WMW. The seeds of watermelon variety NUN 31813 WMW can be grown toproduce hybrid plants and parts thereof (e.g., watermelon fruit). Thehybrid watermelon variety NUN 31813 WMW can be propagated by seeds orvegetatively.

The hybrid variety is uniform and genetically stable. This has beenestablished through evaluation of horticultural characteristics. Severalhybrid seed production events resulted in no observable deviation ingenetic stability. Coupled with the confirmation of genetic stability ofthe female and male parents the Applicant has concluded that watermelonvariety NUN 31813 WMW is uniform and stable.

DEPOSIT INFORMATION

A total of 2500 seeds of the hybrid variety NUN 31813 WMW has beendeposited according to the Budapest Treaty by Nunhems B.V. on ______ atthe NCIMB Ltd., Ferguson Building, Craibstone Estate, Bucksburn,Aberdeen AB21 9YA, United Kingdom (NCIMB). The deposit has been assignedNCIMB number ______. A statement indicating the viability of the samplehas been provided. A deposit of watermelon variety NUN 31813 WMW and ofthe male and female parent line is also maintained at Nunhems B.V. Theseed lot number for watermelon variety NUN 31813 WMW is 29671001002.

The deposit will be maintained in NCIMB for a period of 30 years, or 5years after the most recent request, or for the enforceable life of thepatent whichever is longer and will be replaced if it ever becomesnonviable during that period. Access to the deposits will be availableduring the pendency of this application to persons determined by theDirector of the U.S. Patent Office to be entitled thereto upon request.Subject to 37 C.F.R. § 1.808(b), all restrictions imposed by thedepositor on the availability to the public of the deposited materialwill be irrevocably removed upon the granting of the patent. Applicantdoes not waive any rights granted under this patent on this applicationor under the Plant Variety Protection Act (7 U.S.C. § 2321 et seq.).Accordingly, the requirements of 37 CFR § 1.801-1.809 have beensatisfied.

Characteristics of Watermelon Variety NUN 31813 WMW

The most similar variety to NUN 31813 WMW refers to variety NUN 31208WMW, a variety from Nunhems B.V., with the commercial name Embasy.

In Tables 1 and 2, a comparison between watermelon variety NUN 31813 WMWand the Reference variety is shown based on a trial in the USA. Triallocation: Esparto, Calif., USA; Seeding date: Apr. 21, 2020;Transplanting date: Jun. 3, 2020; Harvesting date: Aug. 12, 2020. InTable 3, the distinguishing characteristics between watermelon varietyNUN 31813 WMW and the Reference Variety are shown.

One replication of 20 plants per variety, from which at least 15 plantsor plant parts were randomly selected and were used to measurecharacteristics. For numerical characteristics, averages werecalculated. For non-numerical characteristics, the type/degree weredetermined. Similarity and differences between two different plant linesor varieties can be determined by comparing the number of morphologicaland/or physiological characteristics (e.g., characteristics as listed inTables 1 and 2) that are the same (i.e., statistically not significantlydifferent) or that are different (i.e., statistically significantlydifferent) between the two plant lines or varieties using plants grownunder the same environmental conditions. A numerical characteristic isconsidered to be “the same” when the value for a numeric characteristicis not significantly different at the 1% (p<0.01) or 5% (p<0.05)significance level, using T-test, a standard method known to the skilledperson. A non-numerical or “degree” or “type” characteristic isconsidered “the same” when the values have the same “degree” or “type”when scored using USDA and/or UPOV descriptors, for plants are grownunder the same environmental conditions. In one aspect, a statisticalanalysis using the T-Test at 5% significance level is provided (see,Tables 4-18).

In one aspect, the disclosure provides a watermelon plant having thephysiological and morphological characteristics of watermelon varietyNUN 31813 WMW as presented in Tables 1-2, when grown under the sameenvironmental conditions.

TABLE 1 Objective Description of Watermelon Variety NUN 31813 WMW andReference Variety (USDA Descriptors) Application Variety ReferenceVariety Characteristics (NUN 31813 WMW) (NUN 31208 WMW) General FruitType: Fruit type: Round small Oblong Oblong, Round Large, Round small(icebox), Other Maturity: Days relative maturity: 77 days 80-90 daysMaturity category: Medium Medium Early, Medium, Late Ploidy: Diploid,Tetrapioid, Triploid Triploid Triploid Plant: Plant sex form: MonoeciousMonoecious Monoecious, Andromonoecious Stem: Stem shape (cross section:)Angular Angular Round, Angular Diameter at second node (mm): 9.42 mm10.92 mm Stem surface: Scabrous Scabrous Glabrous, Scabrous, Pubescent,Bristled Leaf: Leaf shape: Ovate Ovate Ovate, Obovate, Round Leaf lobes:Lobed Lobed None; Lobed Leaf length (cm): 17.02 cm 15.88 cm Leaf width(cm): 16.99 cm 17.60 mm Leaf size: Length-width equal Longer than wideLonger than wide, Length-width equal, Wider than long Dorsal surfacepubescence: Pubescent Pubescent Smooth, Pubescent Ventral surfacepubescence: Pubescent Pubescent Smooth, Pubescent Leaf color: Mediumgreen Medium green Light green, Gray green, Medium green, (RHS 138A)(RHS 137A) Dark green Mature Fruit: Fruit shape: Round Oval Round, Oval,Cylindrical Long (cm): 20.67 cm 28.75 cm Diameter at midsection (cm):19.81 cm 22.73 cm Average weight (kg): 3.66 kg 6.75 kg Maximum fruitweight (kg): 4.50 kg 7.90 kg Fruit surface: Smooth Smooth Smooth,Slightly grooved, Deeply grooved Skin color pattern: Stripe Stripe Solid(one color), Stripe, Mottle/net Primary color (ground color): Yellowgreen Yellow green (RHS 146C) (RHS 145C) Secondary color (stripes): Darkgreen Medium green (RHS 147A) (RHS 137A) Rind: Thickness at blossom end(mm): 11.32 mm 12.05 mm Thickness at sides (mm): 12.12 mm 14.19 mmFlesh: Flesh texture: Crisp Crisp Crisp, Soft Flesh color: Red Red (RHS179B) (RHS 179B) Refractometer: % Soluble solids of juice 11.18% 11.65%(Center of fruit) Resistance: Fusarium oxysporum f. sp. niveum Race 0Resistant Absent Fusarium oxysporum f. sp. niveum Race 1 ResistantIntermediate resistance (IR) Fusarium oxysporum f. sp. niveum Race 2Absent Absent Colletotrichum lagenarium Race 0 Absent AbsentColletotrichum lagenarium Race 1 Resistant Intermediate resistance (IR)Colletotrichum lagenarium Race 2 Absent Absent

TABLE 2 Objective Description of Watermelon Variety NUN 31813 WMW andthe Reference Variety (Non-USDA Descriptors) Application VarietyReference Variety Characteristics (NUN 31813 WMW) (NUN 31208 WMW) Leaf:Leaf blade size: Medium Medium Small, Medium, Large Leaf blade - degreeof lobing: Medium Weak to medium Absent or very weak, Weak, Medium,Strong, Very strong Leaf blade-blistering (on 10^(th) to 15^(th) leaf):Weak to medium Medium Weak, Medium, Strong Leaf blade- color of veins:Green Green Green, Yellow Leaf petiole length (cm): 11.56 cm 12.34 cmLeaf petiole width (cm): 5.76 cm 5.66 cm Mature fruit: Fruit shape inlongitudinal section: Broad elliptic Medium elliptic Circular, Broadelliptic, Medium elliptic, Narrow elliptic Depression at base: ShallowShallow Circular, Broad elliptic, Medium elliptic, Narrow elliptic Shapeof apical part: Rounded Rounded Truncate, Truncate to rounded, Rounded,Rounded to acute, Acute Shape at basal part: Rounded Rounded Depressionat apex: Shallow Shallow Absent or shallow, Shallow, Medium, Deep, Verydeep Conspicuousness of veining: Weak Weak Inconspicuousness of veryweakly conspicuous, Weak, Medium, Strong, Very strong Stripes: PresentPresent Absent, Present Pattern of stripes: One colored One colored withveins Only one color; One color and veins, One colored, veins andmarbled, One colored and marbled, Two colored, veins and marbled, Onlyveins Width of stripes: Broad to very broad Broad Very narrow, Narrow,Medium, Broad, Very broad Conspicuousness of stripes: Strong StrongInconspicuousness of very weakly conspicuous, Weak, Medium, Strong, Verystrong Margin of stripes: Diffuse Diffuse Diffuse, Medium, Sharp Size ofinsertion of peduncle: Medium Medium Size of pistil scar: Small SmallGrooving: Absent or very weak Absent or very weak Absent or very weak,Weak, Medium, Very strong Wax layer: Absent or very weak Absent or veryweak Absent or very weak, Medium, Very strong Thickness of pericarp:Medium Medium Very thin, Thin, Medium, Thick, Very thick Pedunclelength, mm: 68.70 mm 75.84 mm Peduncle width, mm: 6.93 mm 8.90 mm Rind:Thickness at stem end (mm): 14.02 mm 17.20 mm Flesh: Penetrometer (kg):2.11 kg 2.08 kg

TABLE 3 Distinguishing Characteristics between Watermelon Variety NUN31813 WMW and the Reference Variety Application Variety ReferenceVariety Characteristics (NUN 31813 WMW) (NUN 31208 WMW) General FruitType: Fruit type: Round small Oblong Oblong, Round Large, Round small(icebox), Other Stem: Diameter at second node (mm): 9.42 mm 10.92 mmLeaf: Leaf length (cm): 17.02 cm 15.88 cm Leaf blade - degree of lobing:Medium Weak to medium Absent or very weak, Weak, Medium, Strong, Verystrong Leaf blade-blistering (on 10^(th) to 15^(th) leaf): Weak tomedium Medium Weak, Medium, Strong Mature fruit: Fruit shape: Round OvalRound, Oval, Cylindrical Long (cm): 20.67 cm 28.75 cm Diameter atmidsection (cm): 19.81 cm 22.73 cm Average weight (kg): 3.66 kg 6.75 kgPrimary color (ground color): Yellow green Yellow green (RHS 146C) (RHS145C) Secondary color (stripes): Dark green Medium green (RHS 147A) (RHS137A) Fruit shape in longitudinal section: Broad elliptic Mediumelliptic Circular, Broad elliptic, Medium elliptic, Narrow ellipticPattern of stripes: One colored One colored with veins Only one color;One color and veins, One colored, veins and marbled, One colored andmarbled, Two colored, veins and marbled, Only veins Width of stripes:Broad to very broad Broad Very narrow, Narrow, Medium, Broad, Very broadPeduncle length, mm: 68.70 mm 75.84 mm Peduncle width, mm: 6.93 mm 8.90mm Rind: Thickness at sides (mm): 12.12 mm 14.19 mm Thickness at stemend (mm): 14.02 mm 17.20 mm Disease resistance: Fusarium oxysporum f.sp. niveum Race Resistant Absent 0

The results of the T-Test show significant differences betweenwatermelon variety NUN 31813 WMW and the Reference Variety for the stemdiameter at second node, mature leaf length, mature fruit length, maturefruit diameter, mature fruit weight, peduncle length, peduncle widththickness at side, and thickness at stem end as shown in Tables 4-12.

Table 4 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.011) on diameter at second node(mm) based on the results of the trial conducted in the US during thetrial season 2020.

TABLE 4 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 6.64 9.19 Max.12.63 13.61 Median 9.17 10.65 Mean 9.42 10.92 Standard deviation 1.591.42

Table 5 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.022) on mature leaf length (cm)based on the results of the trial conducted in the US during the trialseason 2020.

TABLE 5 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 15.20 15.20Max. 18.80 22.30 Median 16.70 18.30 Mean 17.02 18.55 Standard deviation1.10 2.12

Table 6 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p<0.001) on mature fruit length(cm) based on the results of the trial conducted in the US during thetrial season 2020.

TABLE 6 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 18.80 25.90Max. 22.60 34.30 Median 20.80 28.90 Mean 20.67 28.75 Standard deviation1.06 1.93

Table 7 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p<0.001) on mature fruit diameter(cm) based on the results of the trial conducted in the US during thetrial season 2020.

TABLE 7 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 18.50 19.80Max. 21.80 25.70 Median 19.50 22.30 Mean 19.81 22.73 Standard deviation1.09 1.50

Table 8 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p<0.001) on mature fruit weight(kg) based on the results of the trial conducted in the US during thetrial season 2020.

TABLE 8 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 2.90 5.10 Max.4.50 7.90 Median 3.50 6.80 Mean 3.66 6.75 Standard deviation 0.53 0.89

Table 9 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.038) on peduncle length (mm)based on the results of the trial conducted in the US during the trialseason 2020.

TABLE 9 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 54.35 66.04Max. 84.68 90.76 Median 67.58 73.93 Mean 68.70 75.84 Standard deviation10.44 7.24

Table 10 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p<0.001) on peduncle width (mm)based on the results of the trial conducted in the US during the trialseason 2020.

TABLE 10 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 5.62 7.01 Max.9.56 11.02 Median 6.90 8.46 Mean 6.93 8.90 Standard deviation 1.0 1.32

Table 11 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.007) on thickness at side (mm)based on the results of the trial conducted in the US during the trialseason 2020.

TABLE 11 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 9.07 9.62 Max.14.39 19.54 Median 12.02 13.90 Mean 12.12 14.19 Standard deviation 1.492.31

Table 12 shows a significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p<0.001) on thickness at stem end(mm) based on the results of the trial conducted in the US during thetrial season 2020.

TABLE 12 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 11.49 14.14Max. 16.57 22.27 Median 13.98 16.55 Mean 14.02 17.20 Standard deviation1.71 2.46

The results of the T-test Paired show no significant differences betweenwatermelon variety NUN 31813 WMW and the Reference Variety for matureleaf width, petiole length, petiole width, thickness at blossom end,penetrometer reading, and % soluble solids of juice as shown in Tables13-18.

Table 13 shows no significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.199) on mature leaf width (cm)based on the results of the trial conducted in the US during the trialseason 2020.

TABLE 13 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 15.0 15.40Max. 19.0 19.70 Median 17.0 17.30 Mean 16.99 17.60 Standard deviation1.28 1.24

Table 14 shows no significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.105) on petiole length (cm)based on the results of the trial conducted in the US during the trialseason 2020.

TABLE 14 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 9.60 9.80 Max.13.80 14.50 Median 11.70 12.20 Mean 11.56 12.34 Standard deviation 1.141.40

Table 15 shows no significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.591) on petiole width (cm)based on the results of the trial conducted in the US during the trialseason 2020.

TABLE 15 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 4.62 4.91 Max.6.50 6.26 Median 6.01 5.63 Mean 5.76 5.66 Standard deviation 0.67 0.35

Table 16 shows no significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.177) on thickness at blossomend (mm) based on the results of the trial conducted in the US duringthe trial season 2020.

TABLE 16 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 8.01 9.29 Max.13.75 14.63 Median 11.51 11.91 Mean 11.32 12.05 Standard deviation 1.431.47

Table 17 shows no significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.831) on penetrometer reading(kg) based on the results of the trial conducted in the US during thetrial season 2020.

TABLE 17 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 1.50 1.60 Max.2.60 3.0 Median 2.10 2.0 Mean 2.11 2.08 Standard deviation 0.31 0.37

Table 18 shows no significant difference between watermelon variety NUN31813 WMW and the Reference Variety (p=0.054) on % soluble solids ofjuice based on the results of the trial conducted in the US during thetrial season 2020.

TABLE 18 Application Variety Reference Variety Statistical Parameters(NUN 31813 WMW) (NUN 31208 WMW) No. of samples 15 15 Min. 9.90 10.90Max. 12.30 12.70 Median 11.20 11.50 Mean 11.18 11.65 Standard deviation0.69 0.57

1. A plant, plant part, or seed of watermelon variety NUN 31813 WMW,wherein a representative sample of seed of said watermelon variety hasbeen deposited under Accession Number NCIMB ______.
 2. The plant part ofclaim 1, wherein said plant part is a leaf, pollen, an ovule, a fruit, ascion, a root, a rootstock, a cutting, a flower or, a cell.
 3. A seedthat produces the plant of claim
 1. 4. A plant or part thereof grownfrom the seed of claim
 1. 5. A watermelon plant, or a part thereofhaving all the physiological and morphological characteristics of claim1, when grown under the same environmental conditions.
 6. A watermelonplant, or a part thereof, which does not differ from the physiologicaland morphological characteristics of the plant of claim 1 when thenumerical characteristics are determined at the 5% significance leveland identical for non-numerical characteristics when grown under thesame environmental conditions, and wherein a representative sample ofseed of said watermelon variety NUN 31813 WMW has been deposited underAccession Number NCIMB ______.
 7. A tissue or cell culture comprisingregenerable cells of the plant or plant part of claim
 1. 8. The tissueor cell culture according to claim 7, comprising cells or protoplastsderived from a plant part suitable for vegetative reproduction, whereinthe plant part is an embryo, a meristem, a cotyledon, a hypocotyl, aleaf, an anther, a root, a root tip, a pistil, a petiole, a flower, afruit, a stem, or a stalk.
 9. A watermelon plant regenerated from thetissue or cell culture of claim 7, wherein the plant has all of thephysiological and morphological characteristics of the plant of varietyNUN 31813 WMW, when the numerical characteristics are determined at the5% significance level and identical for non-numerical characteristicsfor plants grown under the same environmental conditions, and wherein arepresentative sample of seed of watermelon variety has been depositedunder Accession Number NCIMB ______.
 10. A method of producing the plantof claim 1 or part thereof, said method comprising vegetativelypropagating at least a part of the plant of watermelon variety NUN 31813WMW, wherein a representative sample of seed of said watermelon varietyhas been deposited under Accession Number NCIMB ______.
 11. The methodof claim 10, wherein said vegetative propagation comprises regeneratinga whole plant from a part of the plant of variety NUN 31813 WMW, whereina representative sample of seed of said watermelon variety has beendeposited under Accession Number NCIMB ______.
 12. The method of claim10, wherein said part is a cutting, a cell culture, or a tissue culture.13. A vegetatively propagated plant or part thereof produced by themethod of claim 10, wherein the plant has all of the physiological andmorphological characteristics of the plant of variety NUN 31813 WMW,when the numerical characteristics are determined at the 5% significancelevel and identical for non-numerical characteristics for plants grownunder the same environmental conditions, and wherein a representativesample of seed of watermelon variety has been deposited under AccessionNumber NCIMB ______.
 14. A method of producing a watermelon plant, saidmethod comprising crossing the plant of claim 1 with a second watermelonplant at least once, and selecting a progeny watermelon plant from saidcrossing and optionally allowing the progeny to form seed.
 15. A methodof producing a watermelon plant, said method comprising crossing melonplants and harvesting the resultant seed, wherein at least onewatermelon plant is the plant of claim 1, wherein a representativesample of seed of said watermelon variety NUN 31813 WMW has beendeposited under Accession Number NCIMB ______.
 16. The watermelon seedproduced by the method of claim
 15. 17. The watermelon plant or partthereof produced by growing the seed of claim
 16. 18. A first generationprogeny plant of the plant of claim 1, obtained by selfing orcross-pollinating the plant of claim 1 with another watermelon plant.19. A method of introducing a single locus conversion into the plant ofclaim 1, comprising: a. crossing the plant of claim 1 with a secondwatermelon plant comprising a desired single locus to produce F1 progenyplants; b. selecting F1 progeny plants that have the single locus toproduce selected F1 progeny plants; c. crossing selected F1 progenyplants with watermelon variety NUN 31813 WMW to produce backcrossprogeny plants; d. selecting backcross progeny plants that have thesingle locus conversion and otherwise comprise all of the physiologicaland morphological characteristics of the watermelon variety NUN 31813WMW to produce selected backcross progeny plants; and e. repeating steps(c) and (d) one or more times in succession to produce selected secondor higher backcross progeny plants that comprise the single locus andotherwise comprise all of the physiological and morphologicalcharacteristics of the watermelon variety NUN 31813 WMW, wherein arepresentative sample of seed of said watermelon variety has beendeposited under Accession Number NCIMB ______.
 20. The method of claim19, wherein the single locus confers yield, storage properties, color,flavor, size, firmness, enhanced nutritional quality, post-harvestquality, male sterility, herbicide tolerance, insect resistance, pestresistance, disease resistance, environmental stress tolerance, modifiedcarbohydrate metabolism, modified protein metabolism, or ripening.
 21. Awatermelon plant produced by the method of claim 19, wherein the singlelocus converted plant otherwise has all of the physiological andmorphological characteristics of the plant of watermelon variety NUN31813 WMW, further comprising the single locus conversion.
 22. A methodof introducing a desired trait into the plant of claim 1, said methodcomprising transforming the plant of claim 1 with a transgene thatconfers the desired trait, wherein the desired trait is yield, storageproperties, color, flavor, size, firmness, enhanced nutritional quality,post-harvest quality, male sterility, herbicide tolerance, insectresistance, pest resistance, disease resistance, environmental stresstolerance, modified carbohydrate metabolism, modified proteinmetabolism, or ripening.
 23. A melon plant produced by the method ofclaim 22, wherein the transformed plant otherwise retains all of thephysiological and morphological characteristics of watermelon varietyNUN 31813 WMW and contains the desired trait.
 24. A method of makingdoubled haploid cells of the plant of claim 1, said method comprisingmaking doubled haploid cells from haploid cells from the plant or plantpart of watermelon variety NUN 31813 WMW, wherein a representativesample of seed of said watermelon variety has been deposited underAccession Number NCIMB ______.
 25. A method of grafting the scion orrootstock, comprising attaching a tissue from the scion or rootstock ofclaim 2 to the tissue of a second plant, and optionally regenerating aplant therefrom.
 26. A plant comprising the scion or rootstock of claim2.
 27. A container comprising the plant, plant part, or seed of claim 1.28. A food product, a feed product, or a processed product comprisingthe plant part of claim 2, wherein the plant part is a fruit or a partthereof.
 29. A method of producing a modified watermelon plant having adesired trait, wherein the method comprises mutating the plant or plantpart of claim 1, and selecting a plant with a desired trait, wherein themutated plant contains the desired trait and otherwise retains all ofthe physiological and morphological characteristics of the plant ofvariety NUN 31813 WMW, when the numerical characteristics are determinedat the 5% significance level and identical for non-numericalcharacteristics for plants grown under the same environmentalconditions, wherein a representative sample of seed of said watermelonvariety has been deposited under Accession Number NCIMB ______, andwherein the desired trait is yield, storage properties, color, flavor,size, firmness, enhanced nutritional quality, post-harvest quality, malesterility, herbicide tolerance, insect resistance, pest resistance,disease resistance, environmental stress tolerance, modifiedcarbohydrate metabolism, modified protein metabolism, or ripening, orthe mutation occurs in the intense gene.
 30. A method of producing awatermelon fruit, said method comprising growing the plant of claim 1until it sets fruit; and collecting at least one fruit.
 31. A method ofcollecting a pollen of the plant of claim 1, said method comprisinggrowing the plant of claim 1 until at least one flower contains pollenand collecting the pollen.
 32. A method for determining the genotype ofthe plant of claim 1, said method comprising obtaining a sample ofnucleic acids from said plant and detecting in said nucleic acid aplurality of polymorphisms, thereby determining the genotype of theplant and storing the results of detecting the plurality ofpolymorphisms on a computer readable medium.
 33. A method of producing awatermelon plant derived from the plant of claim 1, comprising: a.preparing a progeny watermelon plant derived from watermelon variety NUN31813 WMW by crossing the plant of claim 1 with itself or with a secondwatermelon plant; b. crossing the progeny plant with itself or a secondwatermelon plant to produce seed of a progeny plant of a subsequentgeneration; c. growing a progeny plant of a subsequent generation fromsaid seed and crossing the progeny plant of a subsequent generation withitself or a second watermelon plant; and d. repeating steps (b) and/or(c) for at least one more generation to produce a melon plant derivedfrom watermelon variety NUN 31813 WMW.